Merge pull request 'feat(android): Phase 1 MVP app — Compose UI, Room, sync' (#2) from feature/android-frontend into main

Reviewed-on: #2

android/README.md

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+# Pantree Android
+
+Android client for Pantree — the app that tells you what you can cook with what you already have.
+
+## Architecture
+
+- **MVVM** — ViewModel + StateFlow, no LiveData
+- **Hilt** — dependency injection
+- **Room** — local cache (pantry items, recipes, shopping lists)
+- **Retrofit + OkHttp** — network layer with JWT interceptor
+- **Jetpack Compose** — declarative UI, Material 3
+- **EncryptedSharedPreferences** — JWT stored at rest
+- **DataStore** — last-sync timestamp
+
+## Module Structure
+
+```
+app/src/main/java/com/pantree/app/
+├── data/
+│   ├── local/          # Room DB, DAOs, entities, TokenStore, SyncPreferences
+│   ├── model/          # API DTOs (request/response)
+│   ├── remote/         # ApiService (Retrofit), AuthInterceptor
+│   └── repository/     # AuthRepository, PantryRepository, RecipeRepository,
+│                       # ShoppingListRepository, SyncRepository
+├── di/                 # Hilt AppModule
+├── sync/               # SyncManager (lifecycle observer)
+├── ui/
+│   ├── components/     # LoadingState, ErrorState, EmptyState, OfflineBanner, PantreeTopBar
+│   ├── navigation/     # Screen sealed class, PantreeNavGraph
+│   ├── screens/
+│   │   ├── auth/       # SplashScreen, SignInScreen, SignUpScreen,
+│   │   │               # ForgotPasswordScreen, ResetPasswordScreen + AuthViewModel
+│   │   ├── pantry/     # PantryScreen + PantryViewModel
+│   │   ├── recipe/     # RecipesScreen, RecipeDetailScreen + RecipeViewModel
+│   │   ├── shopping/   # ShoppingListsScreen, ShoppingListDetailScreen + ShoppingListViewModel
+│   │   └── settings/   # SettingsScreen + SettingsViewModel
+│   └── theme/          # Color, Type, Theme
+└── util/               # Result<T>, safeApiCall, toUserMessage
+```
+
+## UI States
+
+Every screen handles all four states:
+
+| State | Implementation |
+|-------|---------------|
+| **Loading** | `LoadingState` composable — spinner + contextual message |
+| **Error** | `ErrorState` composable — emoji + message + retry button |
+| **Empty** | `EmptyState` composable — emoji + title + subtitle + optional CTA |
+| **Success** | Full content with `LazyColumn` / detail view |
+
+Offline: cached data shown read-only, `OfflineBanner` displayed.
+
+## Sync Strategy
+
+- `SyncManager` implements `DefaultLifecycleObserver` — triggers on `onStart` (app open + foreground)
+- Delta sync via `GET /sync?since=<last_timestamp>`
+- Server timestamp stored in DataStore, used as `since` on next sync
+- Room cache updated; UI observes `Flow<List<Entity>>` — updates automatically
+
+## Setup
+
+1. Set `BASE_URL` in `app/build.gradle` debug/release buildConfigFields
+2. Set `GOOGLE_WEB_CLIENT_ID` for Google Sign-In
+3. Run backend (`npm run dev` from repo root)
+4. `./gradlew assembleDebug`
+
+## Running Tests
+
+```bash
+# Unit tests
+./gradlew test
+
+# Instrumented tests (requires emulator/device)
+./gradlew connectedAndroidTest
+```

android/app/build.gradle

@@ -0,0 +1,128 @@
+plugins {
+    id 'com.android.application'
+    id 'org.jetbrains.kotlin.android'
+    id 'com.google.dagger.hilt.android'
+    id 'com.google.devtools.ksp'
+}
+
+android {
+    namespace 'com.pantree.app'
+    compileSdk 34
+
+    defaultConfig {
+        applicationId "com.pantree.app"
+        minSdk 26
+        targetSdk 34
+        versionCode 1
+        versionName "1.0.0"
+
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+        vectorDrawables {
+            useSupportLibrary true
+        }
+
+        buildConfigField "String", "BASE_URL", '"https://api.pantree.app/v1/"'
+        buildConfigField "String", "GOOGLE_WEB_CLIENT_ID", '"YOUR_GOOGLE_WEB_CLIENT_ID"'
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled true
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+        debug {
+            buildConfigField "String", "BASE_URL", '"http://10.0.2.2:3000/v1/"'
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = '17'
+    }
+
+    buildFeatures {
+        compose true
+        buildConfig true
+    }
+
+    composeOptions {
+        kotlinCompilerExtensionVersion '1.5.11'
+    }
+
+    packaging {
+        resources {
+            excludes += '/META-INF/{AL2.0,LGPL2.1}'
+        }
+    }
+}
+
+dependencies {
+    // Core
+    implementation 'androidx.core:core-ktx:1.13.0'
+    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.7.0'
+    implementation 'androidx.activity:activity-compose:1.9.0'
+
+    // Compose BOM
+    implementation platform('androidx.compose:compose-bom:2024.04.01')
+    implementation 'androidx.compose.ui:ui'
+    implementation 'androidx.compose.ui:ui-graphics'
+    implementation 'androidx.compose.ui:ui-tooling-preview'
+    implementation 'androidx.compose.material3:material3'
+    implementation 'androidx.compose.material:material-icons-extended'
+
+    // Navigation
+    implementation 'androidx.navigation:navigation-compose:2.7.7'
+
+    // Hilt DI
+    implementation 'com.google.dagger:hilt-android:2.51.1'
+    ksp 'com.google.dagger:hilt-android-compiler:2.51.1'
+    implementation 'androidx.hilt:hilt-navigation-compose:1.2.0'
+
+    // Room
+    implementation 'androidx.room:room-runtime:2.6.1'
+    implementation 'androidx.room:room-ktx:2.6.1'
+    ksp 'androidx.room:room-compiler:2.6.1'
+
+    // Retrofit + OkHttp
+    implementation 'com.squareup.retrofit2:retrofit:2.11.0'
+    implementation 'com.squareup.retrofit2:converter-gson:2.11.0'
+    implementation 'com.squareup.okhttp3:okhttp:4.12.0'
+    implementation 'com.squareup.okhttp3:logging-interceptor:4.12.0'
+
+    // Gson
+    implementation 'com.google.code.gson:gson:2.10.1'
+
+    // ViewModel + StateFlow
+    implementation 'androidx.lifecycle:lifecycle-viewmodel-compose:2.7.0'
+    implementation 'androidx.lifecycle:lifecycle-runtime-compose:2.7.0'
+
+    // EncryptedSharedPreferences
+    implementation 'androidx.security:security-crypto:1.1.0-alpha06'
+
+    // Google Identity (One Tap)
+    implementation 'com.google.android.gms:play-services-auth:21.1.1'
+
+    // Coil (image loading)
+    implementation 'io.coil-kt:coil-compose:2.6.0'
+
+    // DataStore
+    implementation 'androidx.datastore:datastore-preferences:1.1.0'
+
+    // Coroutines
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.8.0'
+
+    // Testing
+    testImplementation 'junit:junit:4.13.2'
+    testImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.8.0'
+    testImplementation 'io.mockk:mockk:1.13.10'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
+    androidTestImplementation platform('androidx.compose:compose-bom:2024.04.01')
+    androidTestImplementation 'androidx.compose.ui:ui-test-junit4'
+    debugImplementation 'androidx.compose.ui:ui-tooling'
+    debugImplementation 'androidx.compose.ui:ui-test-manifest'
+}

android/app/src/androidTest/java/com/pantree/app/ui/screens/pantry/PantryScreenTest.kt

@@ -0,0 +1,43 @@
+package com.pantree.app.ui.screens.pantry
+
+import androidx.compose.ui.test.*
+import androidx.compose.ui.test.junit4.createComposeRule
+import com.pantree.app.data.local.entity.PantryItemEntity
+import com.pantree.app.ui.theme.PantreeTheme
+import org.junit.Rule
+import org.junit.Test
+
+class PantryScreenTest {
+
+    @get:Rule
+    val composeTestRule = createComposeRule()
+
+    @Test
+    fun emptyState_showsEmptyMessage() {
+        composeTestRule.setContent {
+            PantreeTheme {
+                EmptyState(
+                    emoji = "\uD83E\uDED9",
+                    title = "Your pantry is empty",
+                    subtitle = "Add ingredients you have on hand."
+                )
+            }
+        }
+        composeTestRule.onNodeWithText("Your pantry is empty").assertIsDisplayed()
+    }
+
+    @Test
+    fun pantryItemCard_displaysNameAndQuantity() {
+        val item = PantryItemEntity(
+            id = "1", itemName = "Flour", quantity = 3,
+            lastModified = "2024-01-01T00:00:00Z", createdAt = "2024-01-01T00:00:00Z"
+        )
+        composeTestRule.setContent {
+            PantreeTheme {
+                PantryItemCard(item = item, onEdit = {}, onDelete = {})
+            }
+        }
+        composeTestRule.onNodeWithText("Flour").assertIsDisplayed()
+        composeTestRule.onNodeWithText("Qty: 3").assertIsDisplayed()
+    }
+}

android/app/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+
+    <application
+        android:name=".PantreeApplication"
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.Pantree"
+        android:usesCleartextTraffic="false">
+
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:theme="@style/Theme.Pantree">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+
+            <!-- Deep link for password reset -->
+            <intent-filter android:autoVerify="true">
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data
+                    android:scheme="https"
+                    android:host="pantree.app"
+                    android:pathPrefix="/reset-password" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

android/app/src/main/java/com/pantree/app/MainActivity.kt

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+package com.pantree.app
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material3.Surface
+import androidx.compose.ui.Modifier
+import com.pantree.app.ui.navigation.PantreeNavGraph
+import com.pantree.app.ui.theme.PantreeTheme
+import dagger.hilt.android.AndroidEntryPoint
+
+@AndroidEntryPoint
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
+        setContent {
+            PantreeTheme {
+                Surface(modifier = Modifier.fillMaxSize()) {
+                    PantreeNavGraph()
+                }
+            }
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/PantreeApplication.kt

@@ -0,0 +1,7 @@
+package com.pantree.app
+
+import android.app.Application
+import dagger.hilt.android.HiltAndroidApp
+
+@HiltAndroidApp
+class PantreeApplication : Application()

android/app/src/main/java/com/pantree/app/data/local/PantreeDatabase.kt

@@ -0,0 +1,29 @@
+package com.pantree.app.data.local
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import com.pantree.app.data.local.dao.PantryDao
+import com.pantree.app.data.local.dao.RecipeDao
+import com.pantree.app.data.local.dao.ShoppingListDao
+import com.pantree.app.data.local.entity.PantryItemEntity
+import com.pantree.app.data.local.entity.RecipeEntity
+import com.pantree.app.data.local.entity.RecipeIngredientEntity
+import com.pantree.app.data.local.entity.ShoppingListEntity
+import com.pantree.app.data.local.entity.ShoppingListItemEntity
+
+@Database(
+    entities = [
+        PantryItemEntity::class,
+        RecipeEntity::class,
+        RecipeIngredientEntity::class,
+        ShoppingListEntity::class,
+        ShoppingListItemEntity::class
+    ],
+    version = 1,
+    exportSchema = false
+)
+abstract class PantreeDatabase : RoomDatabase() {
+    abstract fun pantryDao(): PantryDao
+    abstract fun recipeDao(): RecipeDao
+    abstract fun shoppingListDao(): ShoppingListDao
+}

android/app/src/main/java/com/pantree/app/data/local/SyncPreferences.kt

@@ -0,0 +1,32 @@
+package com.pantree.app.data.local
+
+import android.content.Context
+import androidx.datastore.core.DataStore
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.map
+import javax.inject.Inject
+import javax.inject.Singleton
+
+val Context.dataStore: DataStore<Preferences> by preferencesDataStore(name = "sync_prefs")
+
+@Singleton
+class SyncPreferences @Inject constructor(
+    @ApplicationContext private val context: Context
+) {
+    private val LAST_SYNC_KEY = stringPreferencesKey("last_sync_timestamp")
+
+    val lastSyncTimestamp: Flow<String> = context.dataStore.data.map { prefs ->
+        prefs[LAST_SYNC_KEY] ?: "1970-01-01T00:00:00.000Z"
+    }
+
+    suspend fun updateLastSync(timestamp: String) {
+        context.dataStore.edit { prefs ->
+            prefs[LAST_SYNC_KEY] = timestamp
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/data/local/TokenStore.kt

@@ -0,0 +1,50 @@
+package com.pantree.app.data.local
+
+import android.content.Context
+import androidx.security.crypto.EncryptedSharedPreferences
+import androidx.security.crypto.MasterKey
+import dagger.hilt.android.qualifiers.ApplicationContext
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class TokenStore @Inject constructor(
+    @ApplicationContext private val context: Context
+) {
+    private val masterKey = MasterKey.Builder(context)
+        .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
+        .build()
+
+    private val prefs = EncryptedSharedPreferences.create(
+        context,
+        "pantree_secure_prefs",
+        masterKey,
+        EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+        EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+    )
+
+    fun saveToken(token: String, expiresAt: String) {
+        prefs.edit()
+            .putString(KEY_TOKEN, token)
+            .putString(KEY_EXPIRES_AT, expiresAt)
+            .apply()
+    }
+
+    fun getToken(): String? = prefs.getString(KEY_TOKEN, null)
+
+    fun getExpiresAt(): String? = prefs.getString(KEY_EXPIRES_AT, null)
+
+    fun clearToken() {
+        prefs.edit()
+            .remove(KEY_TOKEN)
+            .remove(KEY_EXPIRES_AT)
+            .apply()
+    }
+
+    fun isLoggedIn(): Boolean = getToken() != null
+
+    companion object {
+        private const val KEY_TOKEN = "jwt_token"
+        private const val KEY_EXPIRES_AT = "jwt_expires_at"
+    }
+}

android/app/src/main/java/com/pantree/app/data/local/dao/PantryDao.kt

@@ -0,0 +1,29 @@
+package com.pantree.app.data.local.dao
+
+import androidx.room.*
+import com.pantree.app.data.local.entity.PantryItemEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface PantryDao {
+    @Query("SELECT * FROM pantry_items ORDER BY item_name ASC")
+    fun getAllItems(): Flow<List<PantryItemEntity>>
+
+    @Query("SELECT * FROM pantry_items WHERE id = :id")
+    suspend fun getItemById(id: String): PantryItemEntity?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertItem(item: PantryItemEntity)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertItems(items: List<PantryItemEntity>)
+
+    @Update
+    suspend fun updateItem(item: PantryItemEntity)
+
+    @Query("DELETE FROM pantry_items WHERE id = :id")
+    suspend fun deleteItemById(id: String)
+
+    @Query("DELETE FROM pantry_items")
+    suspend fun deleteAll()
+}

android/app/src/main/java/com/pantree/app/data/local/dao/RecipeDao.kt

@@ -0,0 +1,30 @@
+package com.pantree.app.data.local.dao
+
+import androidx.room.*
+import com.pantree.app.data.local.entity.RecipeEntity
+import com.pantree.app.data.local.entity.RecipeIngredientEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface RecipeDao {
+    @Query("SELECT * FROM recipes ORDER BY name ASC")
+    fun getAllRecipes(): Flow<List<RecipeEntity>>
+
+    @Query("SELECT * FROM recipes WHERE can_make = 1 ORDER BY name ASC")
+    fun getCanMakeRecipes(): Flow<List<RecipeEntity>>
+
+    @Query("SELECT * FROM recipes WHERE can_make = 0 AND available_ingredient_count > 0 ORDER BY availability_percentage DESC")
+    fun getPartialRecipes(): Flow<List<RecipeEntity>>
+
+    @Query("SELECT * FROM recipe_ingredients WHERE recipe_id = :recipeId")
+    suspend fun getIngredientsForRecipe(recipeId: String): List<RecipeIngredientEntity>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertRecipes(recipes: List<RecipeEntity>)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertIngredients(ingredients: List<RecipeIngredientEntity>)
+
+    @Query("DELETE FROM recipes")
+    suspend fun deleteAll()
+}

android/app/src/main/java/com/pantree/app/data/local/dao/ShoppingListDao.kt

@@ -0,0 +1,39 @@
+package com.pantree.app.data.local.dao
+
+import androidx.room.*
+import com.pantree.app.data.local.entity.ShoppingListEntity
+import com.pantree.app.data.local.entity.ShoppingListItemEntity
+import kotlinx.coroutines.flow.Flow
+
+@Dao
+interface ShoppingListDao {
+    @Query("SELECT * FROM shopping_lists ORDER BY last_modified DESC")
+    fun getAllLists(): Flow<List<ShoppingListEntity>>
+
+    @Query("SELECT * FROM shopping_list_items WHERE shopping_list_id = :listId ORDER BY item_name ASC")
+    fun getItemsForList(listId: String): Flow<List<ShoppingListItemEntity>>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertList(list: ShoppingListEntity)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertLists(lists: List<ShoppingListEntity>)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertItem(item: ShoppingListItemEntity)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertItems(items: List<ShoppingListItemEntity>)
+
+    @Query("DELETE FROM shopping_lists WHERE id = :id")
+    suspend fun deleteListById(id: String)
+
+    @Query("DELETE FROM shopping_list_items WHERE id = :id")
+    suspend fun deleteItemById(id: String)
+
+    @Query("DELETE FROM shopping_list_items WHERE shopping_list_id = :listId")
+    suspend fun deleteItemsForList(listId: String)
+
+    @Query("DELETE FROM shopping_lists")
+    suspend fun deleteAll()
+}

android/app/src/main/java/com/pantree/app/data/local/entity/Entities.kt

@@ -0,0 +1,77 @@
+package com.pantree.app.data.local.entity
+
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.ForeignKey
+import androidx.room.Index
+import androidx.room.PrimaryKey
+
+@Entity(tableName = "pantry_items")
+data class PantryItemEntity(
+    @PrimaryKey val id: String,
+    @ColumnInfo(name = "item_name") val itemName: String,
+    val quantity: Int,
+    @ColumnInfo(name = "last_modified") val lastModified: String,
+    @ColumnInfo(name = "created_at") val createdAt: String
+)
+
+@Entity(tableName = "recipes")
+data class RecipeEntity(
+    @PrimaryKey val id: String,
+    val name: String,
+    val servings: Int,
+    @ColumnInfo(name = "ingredient_count") val ingredientCount: Int,
+    @ColumnInfo(name = "available_ingredient_count") val availableIngredientCount: Int,
+    @ColumnInfo(name = "can_make") val canMake: Boolean,
+    @ColumnInfo(name = "availability_percentage") val availabilityPercentage: Double
+)
+
+@Entity(
+    tableName = "recipe_ingredients",
+    foreignKeys = [ForeignKey(
+        entity = RecipeEntity::class,
+        parentColumns = ["id"],
+        childColumns = ["recipe_id"],
+        onDelete = ForeignKey.CASCADE
+    )],
+    indices = [Index("recipe_id")]
+)
+data class RecipeIngredientEntity(
+    @PrimaryKey val id: String,
+    @ColumnInfo(name = "recipe_id") val recipeId: String,
+    @ColumnInfo(name = "item_name") val itemName: String,
+    val quantity: Double,
+    @ColumnInfo(name = "original_quantity") val originalQuantity: Double,
+    val unit: String,
+    @ColumnInfo(name = "in_pantry") val inPantry: Boolean
+)
+
+@Entity(tableName = "shopping_lists")
+data class ShoppingListEntity(
+    @PrimaryKey val id: String,
+    @ColumnInfo(name = "list_name") val listName: String,
+    @ColumnInfo(name = "item_count") val itemCount: Int,
+    @ColumnInfo(name = "checked_count") val checkedCount: Int,
+    @ColumnInfo(name = "last_modified") val lastModified: String,
+    @ColumnInfo(name = "created_at") val createdAt: String
+)
+
+@Entity(
+    tableName = "shopping_list_items",
+    foreignKeys = [ForeignKey(
+        entity = ShoppingListEntity::class,
+        parentColumns = ["id"],
+        childColumns = ["shopping_list_id"],
+        onDelete = ForeignKey.CASCADE
+    )],
+    indices = [Index("shopping_list_id")]
+)
+data class ShoppingListItemEntity(
+    @PrimaryKey val id: String,
+    @ColumnInfo(name = "shopping_list_id") val shoppingListId: String,
+    @ColumnInfo(name = "item_name") val itemName: String,
+    val quantity: Double,
+    val unit: String,
+    @ColumnInfo(name = "checked_off") val checkedOff: Boolean,
+    @ColumnInfo(name = "last_modified") val lastModified: String
+)

android/app/src/main/java/com/pantree/app/data/model/ApiModels.kt

@@ -0,0 +1,251 @@
+package com.pantree.app.data.model
+
+import com.google.gson.annotations.SerializedName
+
+// ── Auth ──────────────────────────────────────────────────────────────────────
+
+data class SignupRequest(
+    val email: String,
+    val password: String,
+    val name: String
+)
+
+data class SigninRequest(
+    val email: String,
+    val password: String
+)
+
+data class GoogleAuthRequest(
+    @SerializedName("id_token") val idToken: String
+)
+
+data class PasswordResetRequest(
+    val email: String
+)
+
+data class ConfirmPasswordResetRequest(
+    val token: String,
+    @SerializedName("new_password") val newPassword: String
+)
+
+data class AuthResponse(
+    val user: UserDto,
+    val token: String,
+    @SerializedName("expires_at") val expiresAt: String,
+    @SerializedName("is_new_user") val isNewUser: Boolean? = null
+)
+
+data class UserDto(
+    val id: String,
+    val email: String,
+    val name: String,
+    @SerializedName("profile_picture_url") val profilePictureUrl: String?,
+    @SerializedName("deleted_at") val deletedAt: String?,
+    @SerializedName("created_at") val createdAt: String
+)
+
+data class MessageResponse(
+    val message: String,
+    val timestamp: String
+)
+
+data class RestoreAccountResponse(
+    val user: UserDto,
+    val message: String,
+    val timestamp: String
+)
+
+data class ApiError(
+    val error: String,
+    val code: String,
+    val timestamp: String,
+    @SerializedName("deletion_scheduled_at") val deletionScheduledAt: String? = null
+)
+
+// ── Pantry ────────────────────────────────────────────────────────────────────
+
+data class AddPantryItemRequest(
+    @SerializedName("item_name") val itemName: String,
+    val quantity: Int
+)
+
+data class UpdatePantryItemRequest(
+    val quantity: Int
+)
+
+data class PantryItemDto(
+    val id: String,
+    @SerializedName("item_name") val itemName: String,
+    val quantity: Int,
+    @SerializedName("last_modified") val lastModified: String,
+    @SerializedName("created_at") val createdAt: String
+)
+
+data class PantryListResponse(
+    val items: List<PantryItemDto>,
+    @SerializedName("synced_at") val syncedAt: String
+)
+
+data class PantryItemResponse(
+    val item: PantryItemDto,
+    @SerializedName("synced_at") val syncedAt: String
+)
+
+// ── Recipes ───────────────────────────────────────────────────────────────────
+
+data class RecipeSummaryDto(
+    val id: String,
+    val name: String,
+    val servings: Int,
+    @SerializedName("ingredient_count") val ingredientCount: Int,
+    @SerializedName("available_ingredient_count") val availableIngredientCount: Int,
+    @SerializedName("can_make") val canMake: Boolean,
+    @SerializedName("availability_percentage") val availabilityPercentage: Double
+)
+
+data class RecipeIngredientDto(
+    val id: String,
+    @SerializedName("item_name") val itemName: String,
+    val quantity: Double,
+    @SerializedName("original_quantity") val originalQuantity: Double,
+    val unit: String,
+    @SerializedName("in_pantry") val inPantry: Boolean
+)
+
+data class RecipeDetailDto(
+    val id: String,
+    val name: String,
+    val servings: Int,
+    @SerializedName("scaled_servings") val scaledServings: Int,
+    @SerializedName("scale_factor") val scaleFactor: Int,
+    val instructions: String,
+    val ingredients: List<RecipeIngredientDto>,
+    @SerializedName("can_make") val canMake: Boolean,
+    @SerializedName("available_ingredient_count") val availableIngredientCount: Int,
+    @SerializedName("ingredient_count") val ingredientCount: Int
+)
+
+data class PaginationDto(
+    val page: Int,
+    val limit: Int,
+    val total: Int,
+    @SerializedName("total_pages") val totalPages: Int
+)
+
+data class RecipeListResponse(
+    val recipes: List<RecipeSummaryDto>,
+    val pagination: PaginationDto,
+    @SerializedName("synced_at") val syncedAt: String
+)
+
+data class RecipeDetailResponse(
+    val recipe: RecipeDetailDto
+)
+
+// ── Shopping Lists ────────────────────────────────────────────────────────────
+
+data class CreateShoppingListRequest(
+    @SerializedName("list_name") val listName: String
+)
+
+data class AddShoppingListItemRequest(
+    @SerializedName("item_name") val itemName: String,
+    val quantity: Double,
+    val unit: String
+)
+
+data class UpdateShoppingListItemRequest(
+    val quantity: Double? = null,
+    val unit: String? = null,
+    @SerializedName("checked_off") val checkedOff: Boolean? = null
+)
+
+data class AddRecipesToListRequest(
+    @SerializedName("recipe_ids") val recipeIds: List<String>,
+    @SerializedName("scale_factor") val scaleFactor: Int = 1
+)
+
+data class ShoppingListSummaryDto(
+    val id: String,
+    @SerializedName("list_name") val listName: String,
+    @SerializedName("item_count") val itemCount: Int,
+    @SerializedName("checked_count") val checkedCount: Int,
+    @SerializedName("last_modified") val lastModified: String,
+    @SerializedName("created_at") val createdAt: String
+)
+
+data class ShoppingListItemDto(
+    val id: String,
+    @SerializedName("item_name") val itemName: String,
+    val quantity: Double,
+    val unit: String,
+    @SerializedName("checked_off") val checkedOff: Boolean,
+    @SerializedName("last_modified") val lastModified: String,
+    val merged: Boolean? = null
+)
+
+data class ShoppingListDetailDto(
+    val id: String,
+    @SerializedName("list_name") val listName: String,
+    @SerializedName("last_modified") val lastModified: String,
+    @SerializedName("created_at") val createdAt: String,
+    val items: List<ShoppingListItemDto>
+)
+
+data class ShoppingListsResponse(
+    @SerializedName("shopping_lists") val shoppingLists: List<ShoppingListSummaryDto>,
+    @SerializedName("synced_at") val syncedAt: String
+)
+
+data class ShoppingListResponse(
+    @SerializedName("shopping_list") val shoppingList: ShoppingListSummaryDto
+)
+
+data class ShoppingListDetailResponse(
+    @SerializedName("shopping_list") val shoppingList: ShoppingListDetailDto,
+    @SerializedName("synced_at") val syncedAt: String
+)
+
+data class ShoppingListItemResponse(
+    val item: ShoppingListItemDto,
+    @SerializedName("synced_at") val syncedAt: String? = null,
+    val merged: Boolean? = null,
+    @SerializedName("previous_quantity") val previousQuantity: Double? = null
+)
+
+data class AddRecipesResponse(
+    @SerializedName("shopping_list") val shoppingList: ShoppingListDetailDto,
+    @SerializedName("recipes_added") val recipesAdded: Int,
+    @SerializedName("items_merged") val itemsMerged: Int,
+    @SerializedName("items_created") val itemsCreated: Int
+)
+
+// ── Sync ──────────────────────────────────────────────────────────────────────
+
+data class SyncPantryDto(
+    val updated: List<PantryItemDto>,
+    val deleted: List<String>
+)
+
+data class SyncListItemsDto(
+    val updated: List<ShoppingListItemDto>,
+    val deleted: List<String>
+)
+
+data class SyncShoppingListDto(
+    val id: String,
+    @SerializedName("list_name") val listName: String,
+    @SerializedName("last_modified") val lastModified: String,
+    val items: SyncListItemsDto
+)
+
+data class SyncShoppingListsDto(
+    val updated: List<SyncShoppingListDto>,
+    val deleted: List<String>
+)
+
+data class SyncResponse(
+    @SerializedName("server_timestamp") val serverTimestamp: String,
+    val pantry: SyncPantryDto,
+    @SerializedName("shopping_lists") val shoppingLists: SyncShoppingListsDto
+)

android/app/src/main/java/com/pantree/app/data/remote/ApiService.kt

@@ -0,0 +1,108 @@
+package com.pantree.app.data.remote
+
+import com.pantree.app.data.model.*
+import retrofit2.Response
+import retrofit2.http.*
+
+interface ApiService {
+
+    // ── Auth ──────────────────────────────────────────────────────────────────
+
+    @POST("auth/signup")
+    suspend fun signup(@Body request: SignupRequest): Response<AuthResponse>
+
+    @POST("auth/signin")
+    suspend fun signin(@Body request: SigninRequest): Response<AuthResponse>
+
+    @POST("auth/google")
+    suspend fun googleAuth(@Body request: GoogleAuthRequest): Response<AuthResponse>
+
+    @POST("auth/password-reset")
+    suspend fun requestPasswordReset(@Body request: PasswordResetRequest): Response<MessageResponse>
+
+    @PUT("auth/password-reset")
+    suspend fun confirmPasswordReset(@Body request: ConfirmPasswordResetRequest): Response<MessageResponse>
+
+    @DELETE("auth/account")
+    suspend fun deleteAccount(): Response<Unit>
+
+    @POST("auth/restore-account")
+    suspend fun restoreAccount(): Response<RestoreAccountResponse>
+
+    // ── Pantry ────────────────────────────────────────────────────────────────
+
+    @GET("pantry")
+    suspend fun getPantryItems(): Response<PantryListResponse>
+
+    @POST("pantry")
+    suspend fun addPantryItem(@Body request: AddPantryItemRequest): Response<PantryItemResponse>
+
+    @PUT("pantry/{itemId}")
+    suspend fun updatePantryItem(
+        @Path("itemId") itemId: String,
+        @Body request: UpdatePantryItemRequest
+    ): Response<PantryItemResponse>
+
+    @DELETE("pantry/{itemId}")
+    suspend fun deletePantryItem(@Path("itemId") itemId: String): Response<Unit>
+
+    // ── Recipes ───────────────────────────────────────────────────────────────
+
+    @GET("recipes")
+    suspend fun getRecipes(
+        @Query("filter") filter: String = "all",
+        @Query("page") page: Int = 1,
+        @Query("limit") limit: Int = 20,
+        @Query("search") search: String? = null
+    ): Response<RecipeListResponse>
+
+    @GET("recipes/{recipeId}")
+    suspend fun getRecipeById(
+        @Path("recipeId") recipeId: String,
+        @Query("scale") scale: Int = 1
+    ): Response<RecipeDetailResponse>
+
+    // ── Shopping Lists ────────────────────────────────────────────────────────
+
+    @GET("shopping-lists")
+    suspend fun getShoppingLists(): Response<ShoppingListsResponse>
+
+    @POST("shopping-lists")
+    suspend fun createShoppingList(@Body request: CreateShoppingListRequest): Response<ShoppingListResponse>
+
+    @GET("shopping-lists/{listId}")
+    suspend fun getShoppingListById(@Path("listId") listId: String): Response<ShoppingListDetailResponse>
+
+    @DELETE("shopping-lists/{listId}")
+    suspend fun deleteShoppingList(@Path("listId") listId: String): Response<Unit>
+
+    @POST("shopping-lists/{listId}/items")
+    suspend fun addShoppingListItem(
+        @Path("listId") listId: String,
+        @Body request: AddShoppingListItemRequest
+    ): Response<ShoppingListItemResponse>
+
+    @POST("shopping-lists/{listId}/add-recipes")
+    suspend fun addRecipesToShoppingList(
+        @Path("listId") listId: String,
+        @Body request: AddRecipesToListRequest
+    ): Response<AddRecipesResponse>
+
+    @PUT("shopping-lists/{listId}/items/{itemId}")
+    suspend fun updateShoppingListItem(
+        @Path("listId") listId: String,
+        @Path("itemId") itemId: String,
+        @Body request: UpdateShoppingListItemRequest
+    ): Response<ShoppingListItemResponse>
+
+    @DELETE("shopping-lists/{listId}/items/{itemId}")
+    suspend fun deleteShoppingListItem(
+        @Path("listId") listId: String,
+        @Path("itemId") itemId: String
+    ): Response<Unit>
+
+    // ── Sync ──────────────────────────────────────────────────────────────────
+
+    @GET("sync")
+    suspend fun sync(@Query("since") since: String): Response<SyncResponse>
+}

android/app/src/main/java/com/pantree/app/data/remote/AuthInterceptor.kt

@@ -0,0 +1,22 @@
+package com.pantree.app.data.remote
+
+import com.pantree.app.data.local.TokenStore
+import okhttp3.Interceptor
+import okhttp3.Response
+import javax.inject.Inject
+
+class AuthInterceptor @Inject constructor(
+    private val tokenStore: TokenStore
+) : Interceptor {
+    override fun intercept(chain: Interceptor.Chain): Response {
+        val token = tokenStore.getToken()
+        val request = if (token != null) {
+            chain.request().newBuilder()
+                .addHeader("Authorization", "Bearer $token")
+                .build()
+        } else {
+            chain.request()
+        }
+        return chain.proceed(request)
+    }
+}

android/app/src/main/java/com/pantree/app/data/repository/AuthRepository.kt

@@ -0,0 +1,64 @@
+package com.pantree.app.data.repository
+
+import com.google.gson.Gson
+import com.pantree.app.data.model.ApiError
+import com.pantree.app.data.model.AuthResponse
+import com.pantree.app.data.model.ConfirmPasswordResetRequest
+import com.pantree.app.data.model.GoogleAuthRequest
+import com.pantree.app.data.model.MessageResponse
+import com.pantree.app.data.model.PasswordResetRequest
+import com.pantree.app.data.model.RestoreAccountResponse
+import com.pantree.app.data.model.SigninRequest
+import com.pantree.app.data.model.SignupRequest
+import com.pantree.app.data.local.TokenStore
+import com.pantree.app.data.remote.ApiService
+import com.pantree.app.util.Result
+import com.pantree.app.util.safeApiCall
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class AuthRepository @Inject constructor(
+    private val api: ApiService,
+    private val tokenStore: TokenStore,
+    private val gson: Gson
+) {
+    suspend fun signup(email: String, password: String, name: String): Result<AuthResponse> {
+        val result = safeApiCall(gson) { api.signup(SignupRequest(email, password, name)) }
+        if (result is Result.Success) {
+            tokenStore.saveToken(result.data.token, result.data.expiresAt)
+        }
+        return result
+    }
+
+    suspend fun signin(email: String, password: String): Result<AuthResponse> {
+        val result = safeApiCall(gson) { api.signin(SigninRequest(email, password)) }
+        if (result is Result.Success) {
+            tokenStore.saveToken(result.data.token, result.data.expiresAt)
+        }
+        return result
+    }
+
+    suspend fun googleAuth(idToken: String): Result<AuthResponse> {
+        val result = safeApiCall(gson) { api.googleAuth(GoogleAuthRequest(idToken)) }
+        if (result is Result.Success) {
+            tokenStore.saveToken(result.data.token, result.data.expiresAt)
+        }
+        return result
+    }
+
+    suspend fun requestPasswordReset(email: String): Result<MessageResponse> =
+        safeApiCall(gson) { api.requestPasswordReset(PasswordResetRequest(email)) }
+
+    suspend fun confirmPasswordReset(token: String, newPassword: String): Result<MessageResponse> =
+        safeApiCall(gson) { api.confirmPasswordReset(ConfirmPasswordResetRequest(token, newPassword)) }
+
+    suspend fun deleteAccount(): Result<Unit> =
+        safeApiCall(gson) { api.deleteAccount() }
+
+    suspend fun restoreAccount(): Result<RestoreAccountResponse> =
+        safeApiCall(gson) { api.restoreAccount() }
+
+    fun logout() = tokenStore.clearToken()
+    fun isLoggedIn() = tokenStore.isLoggedIn()
+}

android/app/src/main/java/com/pantree/app/data/repository/PantryRepository.kt

@@ -0,0 +1,63 @@
+package com.pantree.app.data.repository
+
+import com.google.gson.Gson
+import com.pantree.app.data.local.dao.PantryDao
+import com.pantree.app.data.local.entity.PantryItemEntity
+import com.pantree.app.data.model.AddPantryItemRequest
+import com.pantree.app.data.model.PantryItemDto
+import com.pantree.app.data.model.PantryItemResponse
+import com.pantree.app.data.model.PantryListResponse
+import com.pantree.app.data.model.UpdatePantryItemRequest
+import com.pantree.app.data.remote.ApiService
+import com.pantree.app.util.Result
+import com.pantree.app.util.safeApiCall
+import kotlinx.coroutines.flow.Flow
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class PantryRepository @Inject constructor(
+    private val api: ApiService,
+    private val pantryDao: PantryDao,
+    private val gson: Gson
+) {
+    fun getLocalItems(): Flow<List<PantryItemEntity>> = pantryDao.getAllItems()
+
+    suspend fun fetchAndCacheItems(): Result<PantryListResponse> {
+        val result = safeApiCall(gson) { api.getPantryItems() }
+        if (result is Result.Success) {
+            pantryDao.deleteAll()
+            pantryDao.insertItems(result.data.items.map { it.toEntity() })
+        }
+        return result
+    }
+
+    suspend fun addItem(name: String, quantity: Int): Result<PantryItemResponse> {
+        val result = safeApiCall(gson) { api.addPantryItem(AddPantryItemRequest(name, quantity)) }
+        if (result is Result.Success) {
+            pantryDao.insertItem(result.data.item.toEntity())
+        }
+        return result
+    }
+
+    suspend fun updateItem(id: String, quantity: Int): Result<PantryItemResponse> {
+        val result = safeApiCall(gson) { api.updatePantryItem(id, UpdatePantryItemRequest(quantity)) }
+        if (result is Result.Success) {
+            pantryDao.insertItem(result.data.item.toEntity())
+        }
+        return result
+    }
+
+    suspend fun deleteItem(id: String): Result<Unit> {
+        val result = safeApiCall(gson) { api.deletePantryItem(id) }
+        if (result is Result.Success) {
+            pantryDao.deleteItemById(id)
+        }
+        return result
+    }
+
+    private fun PantryItemDto.toEntity() = PantryItemEntity(
+        id = id, itemName = itemName, quantity = quantity,
+        lastModified = lastModified, createdAt = createdAt
+    )
+}

android/app/src/main/java/com/pantree/app/data/repository/RecipeRepository.kt

@@ -0,0 +1,50 @@
+package com.pantree.app.data.repository
+
+import com.google.gson.Gson
+import com.pantree.app.data.local.dao.RecipeDao
+import com.pantree.app.data.local.entity.RecipeEntity
+import com.pantree.app.data.local.entity.RecipeIngredientEntity
+import com.pantree.app.data.model.RecipeDetailResponse
+import com.pantree.app.data.model.RecipeListResponse
+import com.pantree.app.data.model.RecipeSummaryDto
+import com.pantree.app.data.remote.ApiService
+import com.pantree.app.util.Result
+import com.pantree.app.util.safeApiCall
+import kotlinx.coroutines.flow.Flow
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class RecipeRepository @Inject constructor(
+    private val api: ApiService,
+    private val recipeDao: RecipeDao,
+    private val gson: Gson
+) {
+    fun getLocalRecipes(): Flow<List<RecipeEntity>> = recipeDao.getAllRecipes()
+    fun getCanMakeRecipes(): Flow<List<RecipeEntity>> = recipeDao.getCanMakeRecipes()
+    fun getPartialRecipes(): Flow<List<RecipeEntity>> = recipeDao.getPartialRecipes()
+
+    suspend fun fetchRecipes(
+        filter: String = "all",
+        page: Int = 1,
+        search: String? = null
+    ): Result<RecipeListResponse> {
+        val result = safeApiCall(gson) { api.getRecipes(filter, page, 20, search) }
+        if (result is Result.Success && page == 1) {
+            recipeDao.deleteAll()
+            recipeDao.insertRecipes(result.data.recipes.map { it.toEntity() })
+        }
+        return result
+    }
+
+    suspend fun getRecipeById(id: String, scale: Int = 1): Result<RecipeDetailResponse> =
+        safeApiCall(gson) { api.getRecipeById(id, scale) }
+
+    private fun RecipeSummaryDto.toEntity() = RecipeEntity(
+        id = id, name = name, servings = servings,
+        ingredientCount = ingredientCount,
+        availableIngredientCount = availableIngredientCount,
+        canMake = canMake,
+        availabilityPercentage = availabilityPercentage
+    )
+}

android/app/src/main/java/com/pantree/app/data/repository/ShoppingListRepository.kt

@@ -0,0 +1,93 @@
+package com.pantree.app.data.repository
+
+import com.google.gson.Gson
+import com.pantree.app.data.local.dao.ShoppingListDao
+import com.pantree.app.data.local.entity.ShoppingListEntity
+import com.pantree.app.data.local.entity.ShoppingListItemEntity
+import com.pantree.app.data.model.*
+import com.pantree.app.data.remote.ApiService
+import com.pantree.app.util.Result
+import com.pantree.app.util.safeApiCall
+import kotlinx.coroutines.flow.Flow
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class ShoppingListRepository @Inject constructor(
+    private val api: ApiService,
+    private val shoppingListDao: ShoppingListDao,
+    private val gson: Gson
+) {
+    fun getLocalLists(): Flow<List<ShoppingListEntity>> = shoppingListDao.getAllLists()
+    fun getLocalItems(listId: String): Flow<List<ShoppingListItemEntity>> =
+        shoppingListDao.getItemsForList(listId)
+
+    suspend fun fetchLists(): Result<ShoppingListsResponse> {
+        val result = safeApiCall(gson) { api.getShoppingLists() }
+        if (result is Result.Success) {
+            shoppingListDao.deleteAll()
+            shoppingListDao.insertLists(result.data.shoppingLists.map { it.toEntity() })
+        }
+        return result
+    }
+
+    suspend fun createList(name: String): Result<ShoppingListResponse> {
+        val result = safeApiCall(gson) { api.createShoppingList(CreateShoppingListRequest(name)) }
+        if (result is Result.Success) {
+            shoppingListDao.insertList(result.data.shoppingList.toEntity())
+        }
+        return result
+    }
+
+    suspend fun fetchListById(listId: String): Result<ShoppingListDetailResponse> {
+        val result = safeApiCall(gson) { api.getShoppingListById(listId) }
+        if (result is Result.Success) {
+            shoppingListDao.deleteItemsForList(listId)
+            shoppingListDao.insertItems(result.data.shoppingList.items.map { it.toEntity(listId) })
+        }
+        return result
+    }
+
+    suspend fun deleteList(listId: String): Result<Unit> {
+        val result = safeApiCall(gson) { api.deleteShoppingList(listId) }
+        if (result is Result.Success) shoppingListDao.deleteListById(listId)
+        return result
+    }
+
+    suspend fun addItem(listId: String, name: String, quantity: Double, unit: String): Result<ShoppingListItemResponse> {
+        val result = safeApiCall(gson) { api.addShoppingListItem(listId, AddShoppingListItemRequest(name, quantity, unit)) }
+        if (result is Result.Success) shoppingListDao.insertItem(result.data.item.toEntity(listId))
+        return result
+    }
+
+    suspend fun addRecipesToList(listId: String, recipeIds: List<String>, scaleFactor: Int): Result<AddRecipesResponse> {
+        val result = safeApiCall(gson) { api.addRecipesToShoppingList(listId, AddRecipesToListRequest(recipeIds, scaleFactor)) }
+        if (result is Result.Success) {
+            shoppingListDao.deleteItemsForList(listId)
+            shoppingListDao.insertItems(result.data.shoppingList.items.map { it.toEntity(listId) })
+        }
+        return result
+    }
+
+    suspend fun updateItem(listId: String, itemId: String, quantity: Double? = null, unit: String? = null, checkedOff: Boolean? = null): Result<ShoppingListItemResponse> {
+        val result = safeApiCall(gson) { api.updateShoppingListItem(listId, itemId, UpdateShoppingListItemRequest(quantity, unit, checkedOff)) }
+        if (result is Result.Success) shoppingListDao.insertItem(result.data.item.toEntity(listId))
+        return result
+    }
+
+    suspend fun deleteItem(listId: String, itemId: String): Result<Unit> {
+        val result = safeApiCall(gson) { api.deleteShoppingListItem(listId, itemId) }
+        if (result is Result.Success) shoppingListDao.deleteItemById(itemId)
+        return result
+    }
+
+    private fun ShoppingListSummaryDto.toEntity() = ShoppingListEntity(
+        id = id, listName = listName, itemCount = itemCount,
+        checkedCount = checkedCount, lastModified = lastModified, createdAt = createdAt
+    )
+
+    private fun ShoppingListItemDto.toEntity(listId: String) = ShoppingListItemEntity(
+        id = id, shoppingListId = listId, itemName = itemName,
+        quantity = quantity, unit = unit, checkedOff = checkedOff, lastModified = lastModified
+    )
+}

android/app/src/main/java/com/pantree/app/data/repository/SyncRepository.kt

@@ -0,0 +1,65 @@
+package com.pantree.app.data.repository
+
+import com.google.gson.Gson
+import com.pantree.app.data.local.SyncPreferences
+import com.pantree.app.data.local.dao.PantryDao
+import com.pantree.app.data.local.dao.ShoppingListDao
+import com.pantree.app.data.local.entity.PantryItemEntity
+import com.pantree.app.data.local.entity.ShoppingListEntity
+import com.pantree.app.data.local.entity.ShoppingListItemEntity
+import com.pantree.app.data.model.SyncResponse
+import com.pantree.app.data.remote.ApiService
+import com.pantree.app.util.Result
+import com.pantree.app.util.safeApiCall
+import kotlinx.coroutines.flow.first
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class SyncRepository @Inject constructor(
+    private val api: ApiService,
+    private val pantryDao: PantryDao,
+    private val shoppingListDao: ShoppingListDao,
+    private val syncPreferences: SyncPreferences,
+    private val gson: Gson
+) {
+    suspend fun sync(): Result<SyncResponse> {
+        val since = syncPreferences.lastSyncTimestamp.first()
+        val result = safeApiCall(gson) { api.sync(since) }
+        if (result is Result.Success) {
+            val data = result.data
+            // Apply pantry delta
+            data.pantry.updated.forEach {
+                pantryDao.insertItem(PantryItemEntity(it.id, it.itemName, it.quantity, it.lastModified, it.createdAt))
+            }
+            data.pantry.deleted.forEach { pantryDao.deleteItemById(it) }
+
+            // Apply shopping list delta
+            data.shoppingLists.updated.forEach { list ->
+                shoppingListDao.insertList(
+                    ShoppingListEntity(
+                        id = list.id, listName = list.listName,
+                        itemCount = list.items.updated.size,
+                        checkedCount = list.items.updated.count { it.checkedOff },
+                        lastModified = list.lastModified, createdAt = list.lastModified
+                    )
+                )
+                list.items.updated.forEach { item ->
+                    shoppingListDao.insertItem(
+                        ShoppingListItemEntity(
+                            id = item.id, shoppingListId = list.id,
+                            itemName = item.itemName, quantity = item.quantity,
+                            unit = item.unit, checkedOff = item.checkedOff,
+                            lastModified = item.lastModified
+                        )
+                    )
+                }
+                list.items.deleted.forEach { shoppingListDao.deleteItemById(it) }
+            }
+            data.shoppingLists.deleted.forEach { shoppingListDao.deleteListById(it) }
+
+            syncPreferences.updateLastSync(data.serverTimestamp)
+        }
+        return result
+    }
+}

android/app/src/main/java/com/pantree/app/di/AppModule.kt

@@ -0,0 +1,75 @@
+package com.pantree.app.di
+
+import android.content.Context
+import androidx.room.Room
+import com.google.gson.Gson
+import com.google.gson.GsonBuilder
+import com.pantree.app.BuildConfig
+import com.pantree.app.data.local.PantreeDatabase
+import com.pantree.app.data.local.TokenStore
+import com.pantree.app.data.local.dao.PantryDao
+import com.pantree.app.data.local.dao.RecipeDao
+import com.pantree.app.data.local.dao.ShoppingListDao
+import com.pantree.app.data.remote.ApiService
+import com.pantree.app.data.remote.AuthInterceptor
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import retrofit2.Retrofit
+import retrofit2.converter.gson.GsonConverterFactory
+import java.util.concurrent.TimeUnit
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object AppModule {
+
+    @Provides
+    @Singleton
+    fun provideGson(): Gson = GsonBuilder().create()
+
+    @Provides
+    @Singleton
+    fun provideOkHttpClient(authInterceptor: AuthInterceptor): OkHttpClient {
+        val logging = HttpLoggingInterceptor().apply {
+            level = if (BuildConfig.DEBUG) HttpLoggingInterceptor.Level.BODY
+                    else HttpLoggingInterceptor.Level.NONE
+        }
+        return OkHttpClient.Builder()
+            .addInterceptor(authInterceptor)
+            .addInterceptor(logging)
+            .connectTimeout(30, TimeUnit.SECONDS)
+            .readTimeout(30, TimeUnit.SECONDS)
+            .writeTimeout(30, TimeUnit.SECONDS)
+            .build()
+    }
+
+    @Provides
+    @Singleton
+    fun provideRetrofit(okHttpClient: OkHttpClient, gson: Gson): Retrofit =
+        Retrofit.Builder()
+            .baseUrl(BuildConfig.BASE_URL)
+            .client(okHttpClient)
+            .addConverterFactory(GsonConverterFactory.create(gson))
+            .build()
+
+    @Provides
+    @Singleton
+    fun provideApiService(retrofit: Retrofit): ApiService =
+        retrofit.create(ApiService::class.java)
+
+    @Provides
+    @Singleton
+    fun provideDatabase(@ApplicationContext context: Context): PantreeDatabase =
+        Room.databaseBuilder(context, PantreeDatabase::class.java, "pantree.db")
+            .fallbackToDestructiveMigration()
+            .build()
+
+    @Provides fun providePantryDao(db: PantreeDatabase): PantryDao = db.pantryDao()
+    @Provides fun provideRecipeDao(db: PantreeDatabase): RecipeDao = db.recipeDao()
+    @Provides fun provideShoppingListDao(db: PantreeDatabase): ShoppingListDao = db.shoppingListDao()
+}

android/app/src/main/java/com/pantree/app/sync/SyncManager.kt

@@ -0,0 +1,41 @@
+package com.pantree.app.sync
+
+import android.content.Context
+import androidx.lifecycle.DefaultLifecycleObserver
+import androidx.lifecycle.LifecycleOwner
+import com.pantree.app.data.local.TokenStore
+import com.pantree.app.data.repository.SyncRepository
+import com.pantree.app.util.Result
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class SyncManager @Inject constructor(
+    private val syncRepository: SyncRepository,
+    private val tokenStore: TokenStore,
+    @ApplicationContext private val context: Context
+) : DefaultLifecycleObserver {
+
+    private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+
+    /** Called on app open (cold start) and foreground return. */
+    override fun onStart(owner: LifecycleOwner) {
+        triggerSync()
+    }
+
+    fun triggerSync() {
+        if (!tokenStore.isLoggedIn()) return
+        scope.launch {
+            when (val result = syncRepository.sync()) {
+                is Result.Success -> { /* Delta applied to Room, UI observes Flow */ }
+                is Result.Error -> { /* Log silently; cached data still shown */ }
+                is Result.NetworkError -> { /* Offline — cached data shown, offline banner visible */ }
+            }
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/components/CommonComponents.kt

@@ -0,0 +1,147 @@
+package com.pantree.app.ui.components
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+
+@Composable
+fun LoadingState(
+    modifier: Modifier = Modifier,
+    message: String = "Loading..."
+) {
+    Box(
+        modifier = modifier.fillMaxSize(),
+        contentAlignment = Alignment.Center
+    ) {
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            CircularProgressIndicator(color = MaterialTheme.colorScheme.primary)
+            Text(
+                text = message,
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+            )
+        }
+    }
+}
+
+@Composable
+fun ErrorState(
+    message: String,
+    onRetry: (() -> Unit)? = null,
+    modifier: Modifier = Modifier
+) {
+    Box(
+        modifier = modifier.fillMaxSize().padding(32.dp),
+        contentAlignment = Alignment.Center
+    ) {
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            Text(
+                text = "\uD83D\uDE15",
+                style = MaterialTheme.typography.headlineLarge
+            )
+            Text(
+                text = message,
+                style = MaterialTheme.typography.bodyLarge,
+                textAlign = TextAlign.Center,
+                color = MaterialTheme.colorScheme.onSurface
+            )
+            if (onRetry != null) {
+                Button(onClick = onRetry) {
+                    Text("Try again")
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun EmptyState(
+    emoji: String,
+    title: String,
+    subtitle: String,
+    actionLabel: String? = null,
+    onAction: (() -> Unit)? = null,
+    modifier: Modifier = Modifier
+) {
+    Box(
+        modifier = modifier.fillMaxSize().padding(32.dp),
+        contentAlignment = Alignment.Center
+    ) {
+        Column(
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.spacedBy(12.dp)
+        ) {
+            Text(text = emoji, style = MaterialTheme.typography.headlineLarge)
+            Text(
+                text = title,
+                style = MaterialTheme.typography.titleLarge,
+                textAlign = TextAlign.Center
+            )
+            Text(
+                text = subtitle,
+                style = MaterialTheme.typography.bodyMedium,
+                textAlign = TextAlign.Center,
+                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+            )
+            if (actionLabel != null && onAction != null) {
+                Spacer(modifier = Modifier.height(8.dp))
+                Button(onClick = onAction) {
+                    Text(actionLabel)
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun OfflineBanner(modifier: Modifier = Modifier) {
+    Surface(
+        modifier = modifier.fillMaxWidth(),
+        color = MaterialTheme.colorScheme.secondaryContainer
+    ) {
+        Text(
+            text = "\uD83D\uDCF5  You're offline. Showing cached data.",
+            style = MaterialTheme.typography.bodySmall,
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+            color = MaterialTheme.colorScheme.onSecondaryContainer
+        )
+    }
+}
+
+@Composable
+fun PantreeTopBar(
+    title: String,
+    onNavigateBack: (() -> Unit)? = null,
+    actions: @Composable RowScope.() -> Unit = {}
+) {
+    TopAppBar(
+        title = { Text(title, style = MaterialTheme.typography.titleLarge) },
+        navigationIcon = {
+            if (onNavigateBack != null) {
+                IconButton(onClick = onNavigateBack) {
+                    Icon(
+                        imageVector = androidx.compose.material.icons.Icons.Default.ArrowBack,
+                        contentDescription = "Back"
+                    )
+                }
+            }
+        },
+        actions = actions,
+        colors = TopAppBarDefaults.topAppBarColors(
+            containerColor = MaterialTheme.colorScheme.primary,
+            titleContentColor = MaterialTheme.colorScheme.onPrimary,
+            navigationIconContentColor = MaterialTheme.colorScheme.onPrimary,
+            actionIconContentColor = MaterialTheme.colorScheme.onPrimary
+        )
+    )
+}

android/app/src/main/java/com/pantree/app/ui/navigation/PantreeNavGraph.kt

@@ -0,0 +1,120 @@
+package com.pantree.app.ui.navigation
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import androidx.navigation.NavType
+import androidx.navigation.compose.NavHost
+import androidx.navigation.compose.composable
+import androidx.navigation.compose.rememberNavController
+import androidx.navigation.navArgument
+import androidx.navigation.navDeepLink
+import com.pantree.app.ui.screens.auth.ForgotPasswordScreen
+import com.pantree.app.ui.screens.auth.ResetPasswordScreen
+import com.pantree.app.ui.screens.auth.SignInScreen
+import com.pantree.app.ui.screens.auth.SignUpScreen
+import com.pantree.app.ui.screens.auth.SplashScreen
+import com.pantree.app.ui.screens.pantry.PantryScreen
+import com.pantree.app.ui.screens.recipe.RecipeDetailScreen
+import com.pantree.app.ui.screens.recipe.RecipesScreen
+import com.pantree.app.ui.screens.settings.SettingsScreen
+import com.pantree.app.ui.screens.shopping.ShoppingListDetailScreen
+import com.pantree.app.ui.screens.shopping.ShoppingListsScreen
+
+@Composable
+fun PantreeNavGraph() {
+    val navController = rememberNavController()
+
+    NavHost(navController = navController, startDestination = Screen.Splash.route) {
+
+        composable(Screen.Splash.route) {
+            SplashScreen(
+                onNavigateToSignIn = { navController.navigate(Screen.SignIn.route) { popUpTo(Screen.Splash.route) { inclusive = true } } },
+                onNavigateToPantry = { navController.navigate(Screen.Pantry.route) { popUpTo(Screen.Splash.route) { inclusive = true } } }
+            )
+        }
+
+        composable(Screen.SignIn.route) {
+            SignInScreen(
+                onSignInSuccess = { navController.navigate(Screen.Pantry.route) { popUpTo(Screen.SignIn.route) { inclusive = true } } },
+                onNavigateToSignUp = { navController.navigate(Screen.SignUp.route) },
+                onNavigateToForgotPassword = { navController.navigate(Screen.ForgotPassword.route) }
+            )
+        }
+
+        composable(Screen.SignUp.route) {
+            SignUpScreen(
+                onSignUpSuccess = { navController.navigate(Screen.Pantry.route) { popUpTo(Screen.SignIn.route) { inclusive = true } } },
+                onNavigateBack = { navController.popBackStack() }
+            )
+        }
+
+        composable(Screen.ForgotPassword.route) {
+            ForgotPasswordScreen(onNavigateBack = { navController.popBackStack() })
+        }
+
+        composable(
+            route = Screen.ResetPassword.route,
+            arguments = listOf(navArgument("token") { type = NavType.StringType }),
+            deepLinks = listOf(navDeepLink { uriPattern = "https://pantree.app/reset-password?token={token}" })
+        ) { backStackEntry ->
+            ResetPasswordScreen(
+                token = backStackEntry.arguments?.getString("token") ?: "",
+                onResetSuccess = { navController.navigate(Screen.SignIn.route) { popUpTo(0) { inclusive = true } } }
+            )
+        }
+
+        composable(Screen.Pantry.route) {
+            PantryScreen(
+                onNavigateToRecipes = { navController.navigate(Screen.Recipes.route) },
+                onNavigateToShoppingLists = { navController.navigate(Screen.ShoppingLists.route) },
+                onNavigateToSettings = { navController.navigate(Screen.Settings.route) }
+            )
+        }
+
+        composable(Screen.Recipes.route) {
+            RecipesScreen(
+                onRecipeClick = { id -> navController.navigate(Screen.RecipeDetail.createRoute(id)) },
+                onNavigateBack = { navController.popBackStack() }
+            )
+        }
+
+        composable(
+            route = Screen.RecipeDetail.route,
+            arguments = listOf(navArgument("recipeId") { type = NavType.StringType })
+        ) { backStackEntry ->
+            RecipeDetailScreen(
+                recipeId = backStackEntry.arguments?.getString("recipeId") ?: "",
+                onNavigateBack = { navController.popBackStack() },
+                onAddToList = { listId -> navController.navigate(Screen.ShoppingListDetail.createRoute(listId)) }
+            )
+        }
+
+        composable(Screen.ShoppingLists.route) {
+            ShoppingListsScreen(
+                onListClick = { id -> navController.navigate(Screen.ShoppingListDetail.createRoute(id)) },
+                onNavigateBack = { navController.popBackStack() }
+            )
+        }
+
+        composable(
+            route = Screen.ShoppingListDetail.route,
+            arguments = listOf(navArgument("listId") { type = NavType.StringType })
+        ) { backStackEntry ->
+            ShoppingListDetailScreen(
+                listId = backStackEntry.arguments?.getString("listId") ?: "",
+                onNavigateBack = { navController.popBackStack() },
+                onNavigateToRecipes = { navController.navigate(Screen.Recipes.route) }
+            )
+        }
+
+        composable(Screen.Settings.route) {
+            SettingsScreen(
+                onSignOut = { navController.navigate(Screen.SignIn.route) { popUpTo(0) { inclusive = true } } },
+                onNavigateBack = { navController.popBackStack() }
+            )
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/navigation/Screen.kt

@@ -0,0 +1,24 @@
+package com.pantree.app.ui.navigation
+
+sealed class Screen(val route: String) {
+    // Auth
+    object Splash : Screen("splash")
+    object SignIn : Screen("signin")
+    object SignUp : Screen("signup")
+    object ForgotPassword : Screen("forgot_password")
+    object ResetPassword : Screen("reset_password/{token}") {
+        fun createRoute(token: String) = "reset_password/$token"
+    }
+
+    // Main
+    object Pantry : Screen("pantry")
+    object Recipes : Screen("recipes")
+    object RecipeDetail : Screen("recipe/{recipeId}") {
+        fun createRoute(id: String) = "recipe/$id"
+    }
+    object ShoppingLists : Screen("shopping_lists")
+    object ShoppingListDetail : Screen("shopping_list/{listId}") {
+        fun createRoute(id: String) = "shopping_list/$id"
+    }
+    object Settings : Screen("settings")
+}

android/app/src/main/java/com/pantree/app/ui/screens/auth/AuthViewModel.kt

@@ -0,0 +1,93 @@
+package com.pantree.app.ui.screens.auth
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.pantree.app.data.repository.AuthRepository
+import com.pantree.app.util.Result
+import com.pantree.app.util.toUserMessage
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+data class AuthUiState(
+    val isLoading: Boolean = false,
+    val error: String? = null,
+    val success: Boolean = false,
+    val pendingDeletionDate: String? = null
+)
+
+@HiltViewModel
+class AuthViewModel @Inject constructor(
+    private val authRepository: AuthRepository
+) : ViewModel() {
+
+    private val _uiState = MutableStateFlow(AuthUiState())
+    val uiState: StateFlow<AuthUiState> = _uiState.asStateFlow()
+
+    fun signup(email: String, password: String, name: String) {
+        viewModelScope.launch {
+            _uiState.value = AuthUiState(isLoading = true)
+            when (val result = authRepository.signup(email, password, name)) {
+                is Result.Success -> _uiState.value = AuthUiState(success = true)
+                is Result.Error -> _uiState.value = AuthUiState(error = result.toUserMessage())
+                is Result.NetworkError -> _uiState.value = AuthUiState(error = "No internet connection. Please check your network.")
+            }
+        }
+    }
+
+    fun signin(email: String, password: String) {
+        viewModelScope.launch {
+            _uiState.value = AuthUiState(isLoading = true)
+            when (val result = authRepository.signin(email, password)) {
+                is Result.Success -> _uiState.value = AuthUiState(success = true)
+                is Result.Error -> {
+                    val pendingDate = if (result.code == "ACCOUNT_PENDING_DELETION") result.message else null
+                    _uiState.value = AuthUiState(error = result.toUserMessage(), pendingDeletionDate = pendingDate)
+                }
+                is Result.NetworkError -> _uiState.value = AuthUiState(error = "No internet connection. Please check your network.")
+            }
+        }
+    }
+
+    fun googleAuth(idToken: String) {
+        viewModelScope.launch {
+            _uiState.value = AuthUiState(isLoading = true)
+            when (val result = authRepository.googleAuth(idToken)) {
+                is Result.Success -> _uiState.value = AuthUiState(success = true)
+                is Result.Error -> _uiState.value = AuthUiState(error = result.toUserMessage())
+                is Result.NetworkError -> _uiState.value = AuthUiState(error = "No internet connection. Please check your network.")
+            }
+        }
+    }
+
+    fun requestPasswordReset(email: String) {
+        viewModelScope.launch {
+            _uiState.value = AuthUiState(isLoading = true)
+            when (authRepository.requestPasswordReset(email)) {
+                is Result.Success -> _uiState.value = AuthUiState(success = true)
+                is Result.Error -> _uiState.value = AuthUiState(success = true) // Always show success (anti-enumeration)
+                is Result.NetworkError -> _uiState.value = AuthUiState(error = "No internet connection. Please check your network.")
+            }
+        }
+    }
+
+    fun confirmPasswordReset(token: String, newPassword: String) {
+        viewModelScope.launch {
+            _uiState.value = AuthUiState(isLoading = true)
+            when (val result = authRepository.confirmPasswordReset(token, newPassword)) {
+                is Result.Success -> _uiState.value = AuthUiState(success = true)
+                is Result.Error -> _uiState.value = AuthUiState(error = result.toUserMessage())
+                is Result.NetworkError -> _uiState.value = AuthUiState(error = "No internet connection. Please check your network.")
+            }
+        }
+    }
+
+    fun clearError() {
+        _uiState.value = _uiState.value.copy(error = null)
+    }
+
+    fun isLoggedIn() = authRepository.isLoggedIn()
+}

android/app/src/main/java/com/pantree/app/ui/screens/auth/ForgotPasswordScreen.kt

@@ -0,0 +1,153 @@
+package com.pantree.app.ui.screens.auth
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+
+@Composable
+fun ForgotPasswordScreen(
+    onNavigateBack: () -> Unit,
+    viewModel: AuthViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    var email by remember { mutableStateOf("") }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Reset password") },
+                navigationIcon = { IconButton(onClick = onNavigateBack) { Icon(Icons.Default.ArrowBack, "Back") } }
+            )
+        }
+    ) { padding ->
+        Column(
+            modifier = Modifier.fillMaxSize().padding(padding).padding(24.dp),
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            if (uiState.success) {
+                // Success state
+                Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+                    Column(
+                        horizontalAlignment = Alignment.CenterHorizontally,
+                        verticalArrangement = Arrangement.spacedBy(12.dp)
+                    ) {
+                        Text("📬", style = MaterialTheme.typography.headlineLarge)
+                        Text("Check your inbox", style = MaterialTheme.typography.titleLarge)
+                        Text(
+                            "If an account exists for $email, we've sent a reset link. It expires in 1 hour.",
+                            style = MaterialTheme.typography.bodyMedium,
+                            textAlign = TextAlign.Center,
+                            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
+                        )
+                        Spacer(Modifier.height(8.dp))
+                        OutlinedButton(onClick = onNavigateBack) { Text("Back to sign in") }
+                    }
+                }
+            } else {
+                Text("Enter your email and we'll send you a reset link.", style = MaterialTheme.typography.bodyMedium)
+
+                if (uiState.error != null) {
+                    Card(
+                        colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.errorContainer),
+                        modifier = Modifier.fillMaxWidth()
+                    ) {
+                        Text(uiState.error!!, modifier = Modifier.padding(12.dp), color = MaterialTheme.colorScheme.onErrorContainer)
+                    }
+                }
+
+                OutlinedTextField(
+                    value = email,
+                    onValueChange = { email = it },
+                    label = { Text("Email") },
+                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Email),
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                Button(
+                    onClick = { viewModel.requestPasswordReset(email.trim()) },
+                    enabled = !uiState.isLoading && email.isNotBlank(),
+                    modifier = Modifier.fillMaxWidth().height(52.dp)
+                ) {
+                    if (uiState.isLoading) {
+                        CircularProgressIndicator(modifier = Modifier.size(20.dp), color = MaterialTheme.colorScheme.onPrimary)
+                    } else {
+                        Text("Send reset link")
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun ResetPasswordScreen(
+    token: String,
+    onResetSuccess: () -> Unit,
+    viewModel: AuthViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    var newPassword by remember { mutableStateOf("") }
+    var confirmPassword by remember { mutableStateOf("") }
+    val passwordsMatch = newPassword == confirmPassword && newPassword.isNotEmpty()
+
+    LaunchedEffect(uiState.success) {
+        if (uiState.success) onResetSuccess()
+    }
+
+    Scaffold(topBar = { TopAppBar(title = { Text("New password") }) }) { padding ->
+        Column(
+            modifier = Modifier.fillMaxSize().padding(padding).padding(24.dp),
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            Text("Choose a new password for your account.", style = MaterialTheme.typography.bodyMedium)
+
+            if (uiState.error != null) {
+                Card(
+                    colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.errorContainer),
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    Text(uiState.error!!, modifier = Modifier.padding(12.dp), color = MaterialTheme.colorScheme.onErrorContainer)
+                }
+            }
+
+            OutlinedTextField(
+                value = newPassword,
+                onValueChange = { newPassword = it; viewModel.clearError() },
+                label = { Text("New password") },
+                supportingText = { Text("At least 8 characters") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+            OutlinedTextField(
+                value = confirmPassword,
+                onValueChange = { confirmPassword = it },
+                label = { Text("Confirm password") },
+                isError = confirmPassword.isNotEmpty() && !passwordsMatch,
+                supportingText = { if (confirmPassword.isNotEmpty() && !passwordsMatch) Text("Passwords don't match") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+            Button(
+                onClick = { viewModel.confirmPasswordReset(token, newPassword) },
+                enabled = !uiState.isLoading && passwordsMatch && newPassword.length >= 8,
+                modifier = Modifier.fillMaxWidth().height(52.dp)
+            ) {
+                if (uiState.isLoading) {
+                    CircularProgressIndicator(modifier = Modifier.size(20.dp), color = MaterialTheme.colorScheme.onPrimary)
+                } else {
+                    Text("Update password")
+                }
+            }
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/auth/SignInScreen.kt

@@ -0,0 +1,133 @@
+package com.pantree.app.ui.screens.auth
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Visibility
+import androidx.compose.material.icons.filled.VisibilityOff
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.PasswordVisualTransformation
+import androidx.compose.ui.text.input.VisualTransformation
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+
+@Composable
+fun SignInScreen(
+    onSignInSuccess: () -> Unit,
+    onNavigateToSignUp: () -> Unit,
+    onNavigateToForgotPassword: () -> Unit,
+    viewModel: AuthViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    var email by remember { mutableStateOf("") }
+    var password by remember { mutableStateOf("") }
+    var passwordVisible by remember { mutableStateOf(false) }
+
+    LaunchedEffect(uiState.success) {
+        if (uiState.success) onSignInSuccess()
+    }
+
+    Scaffold { padding ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(padding)
+                .padding(horizontal = 24.dp)
+                .verticalScroll(rememberScrollState()),
+            horizontalAlignment = Alignment.CenterHorizontally,
+            verticalArrangement = Arrangement.Center
+        ) {
+            Spacer(Modifier.height(48.dp))
+            Text("🌿", style = MaterialTheme.typography.headlineLarge)
+            Spacer(Modifier.height(8.dp))
+            Text("Welcome back", style = MaterialTheme.typography.headlineMedium)
+            Text(
+                "Sign in to your pantry",
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+            )
+            Spacer(Modifier.height(32.dp))
+
+            // Error banner
+            if (uiState.error != null) {
+                Card(
+                    colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.errorContainer),
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    Text(
+                        text = uiState.error!!,
+                        modifier = Modifier.padding(12.dp),
+                        color = MaterialTheme.colorScheme.onErrorContainer,
+                        style = MaterialTheme.typography.bodyMedium
+                    )
+                }
+                Spacer(Modifier.height(16.dp))
+            }
+
+            OutlinedTextField(
+                value = email,
+                onValueChange = { email = it; viewModel.clearError() },
+                label = { Text("Email") },
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Email),
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+            Spacer(Modifier.height(12.dp))
+            OutlinedTextField(
+                value = password,
+                onValueChange = { password = it; viewModel.clearError() },
+                label = { Text("Password") },
+                singleLine = true,
+                visualTransformation = if (passwordVisible) VisualTransformation.None else PasswordVisualTransformation(),
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Password),
+                trailingIcon = {
+                    IconButton(onClick = { passwordVisible = !passwordVisible }) {
+                        Icon(
+                            imageVector = if (passwordVisible) Icons.Default.VisibilityOff else Icons.Default.Visibility,
+                            contentDescription = if (passwordVisible) "Hide password" else "Show password"
+                        )
+                    }
+                },
+                modifier = Modifier.fillMaxWidth()
+            )
+            TextButton(
+                onClick = onNavigateToForgotPassword,
+                modifier = Modifier.align(Alignment.End)
+            ) {
+                Text("Forgot password?")
+            }
+            Spacer(Modifier.height(8.dp))
+            Button(
+                onClick = { viewModel.signin(email.trim(), password) },
+                enabled = !uiState.isLoading && email.isNotBlank() && password.isNotBlank(),
+                modifier = Modifier.fillMaxWidth().height(52.dp)
+            ) {
+                if (uiState.isLoading) {
+                    CircularProgressIndicator(modifier = Modifier.size(20.dp), color = MaterialTheme.colorScheme.onPrimary)
+                } else {
+                    Text("Sign in")
+                }
+            }
+            Spacer(Modifier.height(16.dp))
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                HorizontalDivider(modifier = Modifier.weight(1f))
+                Text(" or ", style = MaterialTheme.typography.bodySmall, color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.5f))
+                HorizontalDivider(modifier = Modifier.weight(1f))
+            }
+            Spacer(Modifier.height(16.dp))
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Text("Don't have an account?", style = MaterialTheme.typography.bodyMedium)
+                TextButton(onClick = onNavigateToSignUp) { Text("Sign up") }
+            }
+            Spacer(Modifier.height(48.dp))
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/auth/SignUpScreen.kt

@@ -0,0 +1,124 @@
+package com.pantree.app.ui.screens.auth
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.Visibility
+import androidx.compose.material.icons.filled.VisibilityOff
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.input.PasswordVisualTransformation
+import androidx.compose.ui.text.input.VisualTransformation
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+
+@Composable
+fun SignUpScreen(
+    onSignUpSuccess: () -> Unit,
+    onNavigateBack: () -> Unit,
+    viewModel: AuthViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    var name by remember { mutableStateOf("") }
+    var email by remember { mutableStateOf("") }
+    var password by remember { mutableStateOf("") }
+    var passwordVisible by remember { mutableStateOf(false) }
+
+    LaunchedEffect(uiState.success) {
+        if (uiState.success) onSignUpSuccess()
+    }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Create account") },
+                navigationIcon = { IconButton(onClick = onNavigateBack) { Icon(Icons.Default.ArrowBack, "Back") } }
+            )
+        }
+    ) { padding ->
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(padding)
+                .padding(horizontal = 24.dp)
+                .verticalScroll(rememberScrollState()),
+            verticalArrangement = Arrangement.spacedBy(12.dp)
+        ) {
+            Spacer(Modifier.height(16.dp))
+            Text("Let's get you set up", style = MaterialTheme.typography.headlineSmall)
+            Text(
+                "Your pantry awaits.",
+                style = MaterialTheme.typography.bodyMedium,
+                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+            )
+            Spacer(Modifier.height(8.dp))
+
+            if (uiState.error != null) {
+                Card(
+                    colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.errorContainer),
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    Text(
+                        text = uiState.error!!,
+                        modifier = Modifier.padding(12.dp),
+                        color = MaterialTheme.colorScheme.onErrorContainer,
+                        style = MaterialTheme.typography.bodyMedium
+                    )
+                }
+            }
+
+            OutlinedTextField(
+                value = name,
+                onValueChange = { name = it; viewModel.clearError() },
+                label = { Text("Full name") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+            OutlinedTextField(
+                value = email,
+                onValueChange = { email = it; viewModel.clearError() },
+                label = { Text("Email") },
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Email),
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+            OutlinedTextField(
+                value = password,
+                onValueChange = { password = it; viewModel.clearError() },
+                label = { Text("Password") },
+                supportingText = { Text("At least 8 characters") },
+                singleLine = true,
+                visualTransformation = if (passwordVisible) VisualTransformation.None else PasswordVisualTransformation(),
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Password),
+                trailingIcon = {
+                    IconButton(onClick = { passwordVisible = !passwordVisible }) {
+                        Icon(
+                            imageVector = if (passwordVisible) Icons.Default.VisibilityOff else Icons.Default.Visibility,
+                            contentDescription = null
+                        )
+                    }
+                },
+                modifier = Modifier.fillMaxWidth()
+            )
+            Spacer(Modifier.height(8.dp))
+            Button(
+                onClick = { viewModel.signup(email.trim(), password, name.trim()) },
+                enabled = !uiState.isLoading && name.isNotBlank() && email.isNotBlank() && password.length >= 8,
+                modifier = Modifier.fillMaxWidth().height(52.dp)
+            ) {
+                if (uiState.isLoading) {
+                    CircularProgressIndicator(modifier = Modifier.size(20.dp), color = MaterialTheme.colorScheme.onPrimary)
+                } else {
+                    Text("Create account")
+                }
+            }
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/auth/SplashScreen.kt

@@ -0,0 +1,31 @@
+package com.pantree.app.ui.screens.auth
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+
+@Composable
+fun SplashScreen(
+    onNavigateToSignIn: () -> Unit,
+    onNavigateToPantry: () -> Unit,
+    viewModel: AuthViewModel = hiltViewModel()
+) {
+    val isLoggedIn = remember { viewModel.isLoggedIn() }
+
+    LaunchedEffect(Unit) {
+        if (isLoggedIn) onNavigateToPantry() else onNavigateToSignIn()
+    }
+
+    Box(modifier = Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+        Column(horizontalAlignment = Alignment.CenterHorizontally, verticalArrangement = Arrangement.spacedBy(16.dp)) {
+            Text("🌿", style = MaterialTheme.typography.headlineLarge)
+            Text("Pantree", style = MaterialTheme.typography.headlineMedium, color = MaterialTheme.colorScheme.primary)
+            CircularProgressIndicator(modifier = Modifier.size(24.dp))
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/pantry/PantryScreen.kt

@@ -0,0 +1,253 @@
+package com.pantree.app.ui.screens.pantry
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.pantree.app.data.local.entity.PantryItemEntity
+import com.pantree.app.ui.components.EmptyState
+import com.pantree.app.ui.components.ErrorState
+import com.pantree.app.ui.components.LoadingState
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun PantryScreen(
+    onNavigateToRecipes: () -> Unit,
+    onNavigateToShoppingLists: () -> Unit,
+    onNavigateToSettings: () -> Unit,
+    viewModel: PantryViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    var showAddDialog by remember { mutableStateOf(false) }
+    var editingItem by remember { mutableStateOf<PantryItemEntity?>(null) }
+    var deletingItem by remember { mutableStateOf<PantryItemEntity?>(null) }
+    val snackbarHostState = remember { SnackbarHostState() }
+
+    LaunchedEffect(uiState.actionSuccess) {
+        uiState.actionSuccess?.let {
+            snackbarHostState.showSnackbar(it)
+            viewModel.clearActionMessages()
+        }
+    }
+    LaunchedEffect(uiState.actionError) {
+        uiState.actionError?.let {
+            snackbarHostState.showSnackbar(it)
+            viewModel.clearActionMessages()
+        }
+    }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("My Pantry") },
+                actions = {
+                    IconButton(onClick = onNavigateToRecipes) {
+                        Icon(Icons.Default.MenuBook, contentDescription = "Recipes", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                    IconButton(onClick = onNavigateToShoppingLists) {
+                        Icon(Icons.Default.ShoppingCart, contentDescription = "Shopping Lists", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                    IconButton(onClick = onNavigateToSettings) {
+                        Icon(Icons.Default.Settings, contentDescription = "Settings", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                },
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary
+                )
+            )
+        },
+        floatingActionButton = {
+            FloatingActionButton(onClick = { showAddDialog = true }) {
+                Icon(Icons.Default.Add, contentDescription = "Add item")
+            }
+        },
+        snackbarHost = { SnackbarHost(snackbarHostState) }
+    ) { padding ->
+        Box(modifier = Modifier.fillMaxSize().padding(padding)) {
+            when {
+                uiState.isLoading && uiState.items.isEmpty() -> LoadingState(message = "Loading your pantry...")
+                uiState.error != null && uiState.items.isEmpty() -> ErrorState(
+                    message = uiState.error!!,
+                    onRetry = { viewModel.refresh() }
+                )
+                uiState.items.isEmpty() -> EmptyState(
+                    emoji = "\uD83E\uDED9",
+                    title = "Your pantry is empty",
+                    subtitle = "Add ingredients you have on hand and we'll tell you what you can cook.",
+                    actionLabel = "Add your first item",
+                    onAction = { showAddDialog = true }
+                )
+                else -> {
+                    LazyColumn(
+                        contentPadding = PaddingValues(16.dp),
+                        verticalArrangement = Arrangement.spacedBy(8.dp)
+                    ) {
+                        item {
+                            Text(
+                                "${uiState.items.size} item${if (uiState.items.size != 1) "s" else ""}",
+                                style = MaterialTheme.typography.bodySmall,
+                                color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.5f),
+                                modifier = Modifier.padding(bottom = 4.dp)
+                            )
+                        }
+                        items(uiState.items, key = { it.id }) { item ->
+                            PantryItemCard(
+                                item = item,
+                                onEdit = { editingItem = item },
+                                onDelete = { deletingItem = item }
+                            )
+                        }
+                        item { Spacer(Modifier.height(80.dp)) }
+                    }
+                }
+            }
+        }
+    }
+
+    if (showAddDialog) {
+        AddPantryItemDialog(
+            onDismiss = { showAddDialog = false },
+            onConfirm = { name, qty ->
+                viewModel.addItem(name, qty)
+                showAddDialog = false
+            }
+        )
+    }
+
+    editingItem?.let { item ->
+        EditPantryItemDialog(
+            item = item,
+            onDismiss = { editingItem = null },
+            onConfirm = { qty ->
+                viewModel.updateItem(item.id, qty)
+                editingItem = null
+            }
+        )
+    }
+
+    deletingItem?.let { item ->
+        AlertDialog(
+            onDismissRequest = { deletingItem = null },
+            title = { Text("Remove item?") },
+            text = { Text("Remove \"${item.itemName}\" from your pantry?") },
+            confirmButton = {
+                TextButton(onClick = { viewModel.deleteItem(item.id); deletingItem = null }) {
+                    Text("Remove", color = MaterialTheme.colorScheme.error)
+                }
+            },
+            dismissButton = { TextButton(onClick = { deletingItem = null }) { Text("Cancel") } }
+        )
+    }
+}
+
+@Composable
+fun PantryItemCard(
+    item: PantryItemEntity,
+    onEdit: () -> Unit,
+    onDelete: () -> Unit
+) {
+    Card(modifier = Modifier.fillMaxWidth()) {
+        Row(
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 12.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Column(modifier = Modifier.weight(1f)) {
+                Text(item.itemName, style = MaterialTheme.typography.titleMedium)
+                Text(
+                    "Qty: ${item.quantity}",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                )
+            }
+            IconButton(onClick = onEdit) {
+                Icon(Icons.Default.Edit, contentDescription = "Edit", tint = MaterialTheme.colorScheme.primary)
+            }
+            IconButton(onClick = onDelete) {
+                Icon(Icons.Default.Delete, contentDescription = "Delete", tint = MaterialTheme.colorScheme.error)
+            }
+        }
+    }
+}
+
+@Composable
+fun AddPantryItemDialog(onDismiss: () -> Unit, onConfirm: (String, Int) -> Unit) {
+    var name by remember { mutableStateOf("") }
+    var quantityText by remember { mutableStateOf("1") }
+    val quantity = quantityText.toIntOrNull()
+    val isValid = name.isNotBlank() && quantity != null && quantity > 0
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Add to pantry") },
+        text = {
+            Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
+                OutlinedTextField(
+                    value = name,
+                    onValueChange = { name = it },
+                    label = { Text("Item name") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                OutlinedTextField(
+                    value = quantityText,
+                    onValueChange = { quantityText = it },
+                    label = { Text("Quantity") },
+                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+                    singleLine = true,
+                    isError = quantityText.isNotEmpty() && quantity == null,
+                    supportingText = { if (quantityText.isNotEmpty() && quantity == null) Text("Must be a whole number") },
+                    modifier = Modifier.fillMaxWidth()
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = { if (isValid) onConfirm(name, quantity!!) }, enabled = isValid) {
+                Text("Add")
+            }
+        },
+        dismissButton = { TextButton(onClick = onDismiss) { Text("Cancel") } }
+    )
+}
+
+@Composable
+fun EditPantryItemDialog(item: PantryItemEntity, onDismiss: () -> Unit, onConfirm: (Int) -> Unit) {
+    var quantityText by remember { mutableStateOf(item.quantity.toString()) }
+    val quantity = quantityText.toIntOrNull()
+    val isValid = quantity != null && quantity > 0
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Edit quantity") },
+        text = {
+            Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                Text(item.itemName, style = MaterialTheme.typography.titleMedium)
+                OutlinedTextField(
+                    value = quantityText,
+                    onValueChange = { quantityText = it },
+                    label = { Text("Quantity") },
+                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+                    singleLine = true,
+                    isError = quantityText.isNotEmpty() && !isValid,
+                    modifier = Modifier.fillMaxWidth()
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = { if (isValid) onConfirm(quantity!!) }, enabled = isValid) {
+                Text("Save")
+            }
+        },
+        dismissButton = { TextButton(onClick = onDismiss) { Text("Cancel") } }
+    )
+}

android/app/src/main/java/com/pantree/app/ui/screens/pantry/PantryViewModel.kt

@@ -0,0 +1,84 @@
+package com.pantree.app.ui.screens.pantry
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.pantree.app.data.local.entity.PantryItemEntity
+import com.pantree.app.data.repository.PantryRepository
+import com.pantree.app.util.Result
+import com.pantree.app.util.toUserMessage
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+data class PantryUiState(
+    val isLoading: Boolean = false,
+    val items: List<PantryItemEntity> = emptyList(),
+    val error: String? = null,
+    val actionError: String? = null,
+    val actionSuccess: String? = null
+)
+
+@HiltViewModel
+class PantryViewModel @Inject constructor(
+    private val pantryRepository: PantryRepository
+) : ViewModel() {
+
+    private val _uiState = MutableStateFlow(PantryUiState(isLoading = true))
+    val uiState: StateFlow<PantryUiState> = _uiState.asStateFlow()
+
+    init {
+        // Observe local cache immediately
+        viewModelScope.launch {
+            pantryRepository.getLocalItems().collect { items ->
+                _uiState.update { it.copy(items = items, isLoading = false) }
+            }
+        }
+        refresh()
+    }
+
+    fun refresh() {
+        viewModelScope.launch {
+            _uiState.update { it.copy(isLoading = true, error = null) }
+            when (val result = pantryRepository.fetchAndCacheItems()) {
+                is Result.Success -> _uiState.update { it.copy(isLoading = false) }
+                is Result.Error -> _uiState.update { it.copy(isLoading = false, error = result.toUserMessage()) }
+                is Result.NetworkError -> _uiState.update { it.copy(isLoading = false, error = null) } // Show cached, offline banner handled elsewhere
+            }
+        }
+    }
+
+    fun addItem(name: String, quantity: Int) {
+        viewModelScope.launch {
+            when (val result = pantryRepository.addItem(name.trim(), quantity)) {
+                is Result.Success -> _uiState.update { it.copy(actionSuccess = "${result.data.item.itemName} added to pantry.", actionError = null) }
+                is Result.Error -> _uiState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _uiState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun updateItem(id: String, quantity: Int) {
+        viewModelScope.launch {
+            when (val result = pantryRepository.updateItem(id, quantity)) {
+                is Result.Success -> _uiState.update { it.copy(actionSuccess = "Updated.", actionError = null) }
+                is Result.Error -> _uiState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _uiState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun deleteItem(id: String) {
+        viewModelScope.launch {
+            when (val result = pantryRepository.deleteItem(id)) {
+                is Result.Success -> _uiState.update { it.copy(actionSuccess = "Item removed.", actionError = null) }
+                is Result.Error -> _uiState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _uiState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun clearActionMessages() {
+        _uiState.update { it.copy(actionError = null, actionSuccess = null) }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/recipe/RecipeDetailScreen.kt

@@ -0,0 +1,187 @@
+package com.pantree.app.ui.screens.recipe
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.ShoppingCart
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.pantree.app.data.model.RecipeIngredientDto
+import com.pantree.app.ui.components.ErrorState
+import com.pantree.app.ui.components.LoadingState
+import com.pantree.app.ui.theme.SuccessGreen
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun RecipeDetailScreen(
+    recipeId: String,
+    onNavigateBack: () -> Unit,
+    onAddToList: (String) -> Unit,
+    viewModel: RecipeViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.detailState.collectAsStateWithLifecycle()
+
+    LaunchedEffect(recipeId) {
+        viewModel.loadRecipeDetail(recipeId)
+    }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text(uiState.recipe?.name ?: "Recipe") },
+                navigationIcon = {
+                    IconButton(onClick = onNavigateBack) {
+                        Icon(Icons.Default.ArrowBack, "Back", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                },
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary
+                )
+            )
+        }
+    ) { padding ->
+        when {
+            uiState.isLoading -> LoadingState(modifier = Modifier.padding(padding), message = "Loading recipe...")
+            uiState.error != null -> ErrorState(
+                modifier = Modifier.padding(padding),
+                message = uiState.error!!,
+                onRetry = { viewModel.loadRecipeDetail(recipeId) }
+            )
+            uiState.recipe != null -> {
+                val recipe = uiState.recipe!!
+                LazyColumn(
+                    modifier = Modifier.fillMaxSize().padding(padding),
+                    contentPadding = PaddingValues(16.dp),
+                    verticalArrangement = Arrangement.spacedBy(16.dp)
+                ) {
+                    // Header
+                    item {
+                        Row(verticalAlignment = Alignment.CenterVertically) {
+                            Column(modifier = Modifier.weight(1f)) {
+                                Text(recipe.name, style = MaterialTheme.typography.headlineSmall)
+                                Text(
+                                    "${recipe.scaledServings} servings",
+                                    style = MaterialTheme.typography.bodyMedium,
+                                    color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                                )
+                            }
+                            if (recipe.canMake) {
+                                Surface(
+                                    color = SuccessGreen.copy(alpha = 0.15f),
+                                    shape = MaterialTheme.shapes.small
+                                ) {
+                                    Text(
+                                        "\u2705 Ready to cook",
+                                        style = MaterialTheme.typography.labelLarge,
+                                        color = SuccessGreen,
+                                        modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)
+                                    )
+                                }
+                            }
+                        }
+                    }
+
+                    // Scale selector
+                    item {
+                        Card {
+                            Column(modifier = Modifier.padding(16.dp)) {
+                                Text("Scale recipe", style = MaterialTheme.typography.titleSmall)
+                                Spacer(Modifier.height(8.dp))
+                                Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                                    listOf(1, 2, 3).forEach { scale ->
+                                        FilterChip(
+                                            selected = uiState.scaleFactor == scale,
+                                            onClick = { viewModel.setScale(recipeId, scale) },
+                                            label = { Text("${scale}x") }
+                                        )
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    // Ingredients
+                    item {
+                        Text(
+                            "Ingredients (${recipe.availableIngredientCount}/${recipe.ingredientCount} in pantry)",
+                            style = MaterialTheme.typography.titleMedium
+                        )
+                    }
+                    items(recipe.ingredients) { ingredient ->
+                        IngredientRow(ingredient = ingredient)
+                    }
+
+                    // Instructions
+                    item {
+                        Text("Instructions", style = MaterialTheme.typography.titleMedium)
+                    }
+                    item {
+                        Card {
+                            Text(
+                                recipe.instructions,
+                                style = MaterialTheme.typography.bodyMedium,
+                                modifier = Modifier.padding(16.dp)
+                            )
+                        }
+                    }
+
+                    // Add to shopping list button
+                    item {
+                        Spacer(Modifier.height(8.dp))
+                        Button(
+                            onClick = { /* TODO: show list picker dialog */ },
+                            modifier = Modifier.fillMaxWidth()
+                        ) {
+                            Icon(Icons.Default.ShoppingCart, contentDescription = null)
+                            Spacer(Modifier.width(8.dp))
+                            Text("Add to shopping list")
+                        }
+                        Spacer(Modifier.height(16.dp))
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun IngredientRow(ingredient: RecipeIngredientDto) {
+    Row(
+        modifier = Modifier
+            .fillMaxWidth()
+            .background(
+                if (ingredient.inPantry) SuccessGreen.copy(alpha = 0.07f)
+                else MaterialTheme.colorScheme.surface
+            )
+            .padding(horizontal = 4.dp, vertical = 8.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            if (ingredient.inPantry) "\u2705" else "\u274C",
+            modifier = Modifier.width(28.dp)
+        )
+        Column(modifier = Modifier.weight(1f)) {
+            Text(ingredient.itemName, style = MaterialTheme.typography.bodyLarge)
+        }
+        Text(
+            "${formatQuantity(ingredient.quantity)} ${ingredient.unit}",
+            style = MaterialTheme.typography.bodyMedium,
+            color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
+        )
+    }
+}
+
+fun formatQuantity(qty: Double): String {
+    return if (qty == qty.toLong().toDouble()) qty.toLong().toString()
+    else String.format("%.2f", qty).trimEnd('0').trimEnd('.')
+}

android/app/src/main/java/com/pantree/app/ui/screens/recipe/RecipeViewModel.kt

@@ -0,0 +1,83 @@
+package com.pantree.app.ui.screens.recipe
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.pantree.app.data.local.entity.RecipeEntity
+import com.pantree.app.data.model.RecipeDetailDto
+import com.pantree.app.data.repository.RecipeRepository
+import com.pantree.app.util.Result
+import com.pantree.app.util.toUserMessage
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+data class RecipesUiState(
+    val isLoading: Boolean = false,
+    val recipes: List<RecipeEntity> = emptyList(),
+    val error: String? = null,
+    val currentFilter: String = "all",
+    val searchQuery: String = "",
+    val currentPage: Int = 1,
+    val totalPages: Int = 1
+)
+
+data class RecipeDetailUiState(
+    val isLoading: Boolean = false,
+    val recipe: RecipeDetailDto? = null,
+    val error: String? = null,
+    val scaleFactor: Int = 1
+)
+
+@HiltViewModel
+class RecipeViewModel @Inject constructor(
+    private val recipeRepository: RecipeRepository
+) : ViewModel() {
+
+    private val _listState = MutableStateFlow(RecipesUiState(isLoading = true))
+    val listState: StateFlow<RecipesUiState> = _listState.asStateFlow()
+
+    private val _detailState = MutableStateFlow(RecipeDetailUiState())
+    val detailState: StateFlow<RecipeDetailUiState> = _detailState.asStateFlow()
+
+    init {
+        viewModelScope.launch {
+            recipeRepository.getLocalRecipes().collect { recipes ->
+                _listState.update { it.copy(recipes = recipes, isLoading = false) }
+            }
+        }
+        fetchRecipes()
+    }
+
+    fun fetchRecipes(filter: String = _listState.value.currentFilter, search: String? = null, page: Int = 1) {
+        viewModelScope.launch {
+            _listState.update { it.copy(isLoading = true, error = null, currentFilter = filter, searchQuery = search ?: "") }
+            when (val result = recipeRepository.fetchRecipes(filter, page, search)) {
+                is Result.Success -> _listState.update {
+                    it.copy(
+                        isLoading = false,
+                        currentPage = result.data.pagination.page,
+                        totalPages = result.data.pagination.totalPages
+                    )
+                }
+                is Result.Error -> _listState.update { it.copy(isLoading = false, error = result.toUserMessage()) }
+                is Result.NetworkError -> _listState.update { it.copy(isLoading = false) }
+            }
+        }
+    }
+
+    fun loadRecipeDetail(recipeId: String, scale: Int = 1) {
+        viewModelScope.launch {
+            _detailState.value = RecipeDetailUiState(isLoading = true, scaleFactor = scale)
+            when (val result = recipeRepository.getRecipeById(recipeId, scale)) {
+                is Result.Success -> _detailState.value = RecipeDetailUiState(recipe = result.data.recipe, scaleFactor = scale)
+                is Result.Error -> _detailState.value = RecipeDetailUiState(error = result.toUserMessage())
+                is Result.NetworkError -> _detailState.value = RecipeDetailUiState(error = "No internet connection.")
+            }
+        }
+    }
+
+    fun setScale(recipeId: String, scale: Int) {
+        if (scale in 1..3) loadRecipeDetail(recipeId, scale)
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/recipe/RecipesScreen.kt

@@ -0,0 +1,168 @@
+package com.pantree.app.ui.screens.recipe
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.Search
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.pantree.app.data.local.entity.RecipeEntity
+import com.pantree.app.ui.components.EmptyState
+import com.pantree.app.ui.components.ErrorState
+import com.pantree.app.ui.components.LoadingState
+import com.pantree.app.ui.theme.SuccessGreen
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun RecipesScreen(
+    onRecipeClick: (String) -> Unit,
+    onNavigateBack: () -> Unit,
+    viewModel: RecipeViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.listState.collectAsStateWithLifecycle()
+    var searchText by remember { mutableStateOf("") }
+    var showSearch by remember { mutableStateOf(false) }
+
+    Scaffold(
+        topBar = {
+            if (showSearch) {
+                TopAppBar(
+                    title = {
+                        OutlinedTextField(
+                            value = searchText,
+                            onValueChange = {
+                                searchText = it
+                                viewModel.fetchRecipes(search = it.ifBlank { null })
+                            },
+                            placeholder = { Text("Search recipes...") },
+                            singleLine = true,
+                            modifier = Modifier.fillMaxWidth(),
+                            colors = OutlinedTextFieldDefaults.colors(focusedBorderColor = Color.Transparent, unfocusedBorderColor = Color.Transparent)
+                        )
+                    },
+                    navigationIcon = {
+                        IconButton(onClick = { showSearch = false; searchText = ""; viewModel.fetchRecipes() }) {
+                            Icon(Icons.Default.ArrowBack, "Close search", tint = MaterialTheme.colorScheme.onPrimary)
+                        }
+                    },
+                    colors = TopAppBarDefaults.topAppBarColors(containerColor = MaterialTheme.colorScheme.primary)
+                )
+            } else {
+                TopAppBar(
+                    title = { Text("Recipes") },
+                    navigationIcon = { IconButton(onClick = onNavigateBack) { Icon(Icons.Default.ArrowBack, "Back", tint = MaterialTheme.colorScheme.onPrimary) } },
+                    actions = {
+                        IconButton(onClick = { showSearch = true }) {
+                            Icon(Icons.Default.Search, "Search", tint = MaterialTheme.colorScheme.onPrimary)
+                        }
+                    },
+                    colors = TopAppBarDefaults.topAppBarColors(
+                        containerColor = MaterialTheme.colorScheme.primary,
+                        titleContentColor = MaterialTheme.colorScheme.onPrimary
+                    )
+                )
+            }
+        }
+    ) { padding ->
+        Column(modifier = Modifier.fillMaxSize().padding(padding)) {
+            // Filter chips
+            Row(
+                modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp),
+                horizontalArrangement = Arrangement.spacedBy(8.dp)
+            ) {
+                listOf("all" to "All", "can_make" to "Can make", "can_partially_make" to "Partial").forEach { (value, label) ->
+                    FilterChip(
+                        selected = uiState.currentFilter == value,
+                        onClick = { viewModel.fetchRecipes(filter = value) },
+                        label = { Text(label) }
+                    )
+                }
+            }
+
+            when {
+                uiState.isLoading && uiState.recipes.isEmpty() -> LoadingState(message = "Finding recipes...")
+                uiState.error != null && uiState.recipes.isEmpty() -> ErrorState(
+                    message = uiState.error!!,
+                    onRetry = { viewModel.fetchRecipes() }
+                )
+                uiState.recipes.isEmpty() -> EmptyState(
+                    emoji = "\uD83D\uDCDA",
+                    title = when (uiState.currentFilter) {
+                        "can_make" -> "Nothing to cook yet"
+                        "can_partially_make" -> "No partial matches"
+                        else -> "No recipes found"
+                    },
+                    subtitle = when (uiState.currentFilter) {
+                        "can_make" -> "Add more ingredients to your pantry to unlock recipes."
+                        "can_partially_make" -> "Try adding a few more pantry items."
+                        else -> "Try a different search term."
+                    }
+                )
+                else -> {
+                    LazyColumn(
+                        contentPadding = PaddingValues(16.dp),
+                        verticalArrangement = Arrangement.spacedBy(8.dp)
+                    ) {
+                        items(uiState.recipes, key = { it.id }) { recipe ->
+                            RecipeCard(recipe = recipe, onClick = { onRecipeClick(recipe.id) })
+                        }
+                        item { Spacer(Modifier.height(16.dp)) }
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun RecipeCard(recipe: RecipeEntity, onClick: () -> Unit) {
+    Card(modifier = Modifier.fillMaxWidth(), onClick = onClick) {
+        Column(modifier = Modifier.padding(16.dp)) {
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                Text(recipe.name, style = MaterialTheme.typography.titleMedium, modifier = Modifier.weight(1f))
+                if (recipe.canMake) {
+                    Surface(
+                        color = SuccessGreen.copy(alpha = 0.15f),
+                        shape = MaterialTheme.shapes.small
+                    ) {
+                        Text(
+                            "\u2705 Can make",
+                            style = MaterialTheme.typography.labelLarge,
+                            color = SuccessGreen,
+                            modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)
+                        )
+                    }
+                }
+            }
+            Spacer(Modifier.height(8.dp))
+            Row(horizontalArrangement = Arrangement.spacedBy(16.dp)) {
+                Text(
+                    "${recipe.servings} servings",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                )
+                Text(
+                    "${recipe.availableIngredientCount}/${recipe.ingredientCount} ingredients",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = if (recipe.canMake) SuccessGreen else MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                )
+            }
+            if (!recipe.canMake && recipe.ingredientCount > 0) {
+                Spacer(Modifier.height(8.dp))
+                LinearProgressIndicator(
+                    progress = { (recipe.availabilityPercentage / 100f).toFloat() },
+                    modifier = Modifier.fillMaxWidth(),
+                    color = MaterialTheme.colorScheme.primary
+                )
+            }
+        }
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/settings/SettingsScreen.kt

@@ -0,0 +1,132 @@
+package com.pantree.app.ui.screens.settings
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun SettingsScreen(
+    onSignOut: () -> Unit,
+    onNavigateBack: () -> Unit,
+    viewModel: SettingsViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.uiState.collectAsStateWithLifecycle()
+    var showDeleteConfirm by remember { mutableStateOf(false) }
+
+    LaunchedEffect(uiState.signedOut) { if (uiState.signedOut) onSignOut() }
+    LaunchedEffect(uiState.accountDeleted) { if (uiState.accountDeleted) onSignOut() }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Settings") },
+                navigationIcon = {
+                    IconButton(onClick = onNavigateBack) {
+                        Icon(Icons.Default.ArrowBack, "Back", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                },
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary
+                )
+            )
+        }
+    ) { padding ->
+        Column(
+            modifier = Modifier.fillMaxSize().padding(padding).padding(16.dp),
+            verticalArrangement = Arrangement.spacedBy(8.dp)
+        ) {
+            if (uiState.error != null) {
+                Card(
+                    colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.errorContainer),
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    Text(
+                        uiState.error!!,
+                        modifier = Modifier.padding(12.dp),
+                        color = MaterialTheme.colorScheme.onErrorContainer
+                    )
+                }
+            }
+
+            Spacer(Modifier.height(8.dp))
+            Text("Account", style = MaterialTheme.typography.titleSmall, color = MaterialTheme.colorScheme.primary)
+            Spacer(Modifier.height(4.dp))
+
+            Card(modifier = Modifier.fillMaxWidth()) {
+                Column {
+                    ListItem(
+                        headlineContent = { Text("Sign out") },
+                        supportingContent = { Text("You can sign back in anytime.") },
+                        modifier = Modifier.fillMaxWidth()
+                    )
+                    Button(
+                        onClick = { viewModel.signOut() },
+                        modifier = Modifier.fillMaxWidth().padding(horizontal = 16.dp, vertical = 8.dp)
+                    ) {
+                        Text("Sign out")
+                    }
+                }
+            }
+
+            Spacer(Modifier.height(16.dp))
+            Text("Danger zone", style = MaterialTheme.typography.titleSmall, color = MaterialTheme.colorScheme.error)
+            Spacer(Modifier.height(4.dp))
+
+            Card(
+                modifier = Modifier.fillMaxWidth(),
+                colors = CardDefaults.cardColors(containerColor = MaterialTheme.colorScheme.errorContainer.copy(alpha = 0.3f))
+            ) {
+                Column(modifier = Modifier.padding(16.dp), verticalArrangement = Arrangement.spacedBy(8.dp)) {
+                    Text("Delete account", style = MaterialTheme.typography.titleMedium)
+                    Text(
+                        "Your account will be scheduled for deletion. You have 15 days to change your mind — just sign back in.",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.7f)
+                    )
+                    OutlinedButton(
+                        onClick = { showDeleteConfirm = true },
+                        enabled = !uiState.isLoading,
+                        colors = ButtonDefaults.outlinedButtonColors(contentColor = MaterialTheme.colorScheme.error),
+                        modifier = Modifier.fillMaxWidth()
+                    ) {
+                        if (uiState.isLoading) {
+                            CircularProgressIndicator(modifier = Modifier.size(18.dp))
+                        } else {
+                            Text("Delete my account")
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    if (showDeleteConfirm) {
+        AlertDialog(
+            onDismissRequest = { showDeleteConfirm = false },
+            title = { Text("Delete account?") },
+            text = {
+                Text(
+                    "This will schedule your account for permanent deletion in 15 days. " +
+                    "All your pantry items, recipes, and shopping lists will be removed. " +
+                    "Sign back in within 15 days to cancel."
+                )
+            },
+            confirmButton = {
+                TextButton(onClick = { viewModel.deleteAccount(); showDeleteConfirm = false }) {
+                    Text("Yes, delete", color = MaterialTheme.colorScheme.error)
+                }
+            },
+            dismissButton = {
+                TextButton(onClick = { showDeleteConfirm = false }) { Text("Keep my account") }
+            }
+        )
+    }
+}

android/app/src/main/java/com/pantree/app/ui/screens/settings/SettingsViewModel.kt

@@ -0,0 +1,51 @@
+package com.pantree.app.ui.screens.settings
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.pantree.app.data.repository.AuthRepository
+import com.pantree.app.util.Result
+import com.pantree.app.util.toUserMessage
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+data class SettingsUiState(
+    val isLoading: Boolean = false,
+    val error: String? = null,
+    val signedOut: Boolean = false,
+    val accountDeleted: Boolean = false
+)
+
+@HiltViewModel
+class SettingsViewModel @Inject constructor(
+    private val authRepository: AuthRepository
+) : ViewModel() {
+
+    private val _uiState = MutableStateFlow(SettingsUiState())
+    val uiState: StateFlow<SettingsUiState> = _uiState.asStateFlow()
+
+    fun signOut() {
+        authRepository.logout()
+        _uiState.update { it.copy(signedOut = true) }
+    }
+
+    fun deleteAccount() {
+        viewModelScope.launch {
+            _uiState.update { it.copy(isLoading = true) }
+            when (val result = authRepository.deleteAccount()) {
+                is Result.Success -> {
+                    authRepository.logout()
+                    _uiState.update { it.copy(isLoading = false, accountDeleted = true) }
+                }
+                is Result.Error -> _uiState.update { it.copy(isLoading = false, error = result.toUserMessage()) }
+                is Result.NetworkError -> _uiState.update { it.copy(isLoading = false, error = "No internet connection.") }
+            }
+        }
+    }
+
+    fun clearError() = _uiState.update { it.copy(error = null) }
+}

android/app/src/main/java/com/pantree/app/ui/screens/shopping/ShoppingListDetailScreen.kt

@@ -0,0 +1,305 @@
+package com.pantree.app.ui.screens.shopping
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.pantree.app.data.local.entity.ShoppingListItemEntity
+import com.pantree.app.ui.components.EmptyState
+import com.pantree.app.ui.components.ErrorState
+import com.pantree.app.ui.components.LoadingState
+
+val ALLOWED_UNITS = listOf(
+    "cups", "tbsp", "tsp", "oz", "fl_oz",
+    "g", "kg", "ml", "l",
+    "pieces", "slices", "cloves", "pinch",
+    "whole", "can", "package", "bunch"
+)
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ShoppingListDetailScreen(
+    listId: String,
+    onNavigateBack: () -> Unit,
+    onNavigateToRecipes: () -> Unit,
+    viewModel: ShoppingListViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.detailState.collectAsStateWithLifecycle()
+    var showAddItemDialog by remember { mutableStateOf(false) }
+    var deletingItemId by remember { mutableStateOf<String?>(null) }
+    val snackbarHostState = remember { SnackbarHostState() }
+
+    LaunchedEffect(listId) { viewModel.loadListDetail(listId) }
+
+    LaunchedEffect(uiState.actionSuccess) {
+        uiState.actionSuccess?.let { snackbarHostState.showSnackbar(it); viewModel.clearDetailMessages() }
+    }
+    LaunchedEffect(uiState.actionError) {
+        uiState.actionError?.let { snackbarHostState.showSnackbar(it); viewModel.clearDetailMessages() }
+    }
+    LaunchedEffect(uiState.addRecipesSuccess) {
+        uiState.addRecipesSuccess?.let { snackbarHostState.showSnackbar(it); viewModel.clearDetailMessages() }
+    }
+
+    val uncheckedItems = uiState.items.filter { !it.checkedOff }
+    val checkedItems = uiState.items.filter { it.checkedOff }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text(uiState.listName.ifBlank { "Shopping List" }) },
+                navigationIcon = {
+                    IconButton(onClick = onNavigateBack) {
+                        Icon(Icons.Default.ArrowBack, "Back", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                },
+                actions = {
+                    IconButton(onClick = onNavigateToRecipes) {
+                        Icon(Icons.Default.MenuBook, "Add from recipes", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                },
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary
+                )
+            )
+        },
+        floatingActionButton = {
+            FloatingActionButton(onClick = { showAddItemDialog = true }) {
+                Icon(Icons.Default.Add, "Add item")
+            }
+        },
+        snackbarHost = { SnackbarHost(snackbarHostState) }
+    ) { padding ->
+        Box(modifier = Modifier.fillMaxSize().padding(padding)) {
+            when {
+                uiState.isLoading && uiState.items.isEmpty() -> LoadingState(message = "Loading list...")
+                uiState.error != null && uiState.items.isEmpty() -> ErrorState(
+                    message = uiState.error!!,
+                    onRetry = { viewModel.loadListDetail(listId) }
+                )
+                uiState.items.isEmpty() -> EmptyState(
+                    emoji = "\uD83D\uDCCB",
+                    title = "This list is empty",
+                    subtitle = "Add items manually or pull in ingredients from a recipe.",
+                    actionLabel = "Add an item",
+                    onAction = { showAddItemDialog = true }
+                )
+                else -> {
+                    LazyColumn(
+                        contentPadding = PaddingValues(16.dp),
+                        verticalArrangement = Arrangement.spacedBy(6.dp)
+                    ) {
+                        // Progress summary
+                        item {
+                            if (uiState.items.isNotEmpty()) {
+                                val progress = checkedItems.size.toFloat() / uiState.items.size
+                                Column(verticalArrangement = Arrangement.spacedBy(4.dp)) {
+                                    Text(
+                                        "${checkedItems.size} of ${uiState.items.size} checked",
+                                        style = MaterialTheme.typography.bodySmall,
+                                        color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                                    )
+                                    LinearProgressIndicator(
+                                        progress = { progress },
+                                        modifier = Modifier.fillMaxWidth()
+                                    )
+                                    Spacer(Modifier.height(8.dp))
+                                }
+                            }
+                        }
+
+                        // Unchecked items
+                        items(uncheckedItems, key = { it.id }) { item ->
+                            ShoppingListItemRow(
+                                item = item,
+                                onToggle = { viewModel.toggleCheckOff(listId, item) },
+                                onDelete = { deletingItemId = item.id }
+                            )
+                        }
+
+                        // Checked items section
+                        if (checkedItems.isNotEmpty()) {
+                            item {
+                                Spacer(Modifier.height(8.dp))
+                                Text(
+                                    "In cart (${checkedItems.size})",
+                                    style = MaterialTheme.typography.labelLarge,
+                                    color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.5f)
+                                )
+                                Spacer(Modifier.height(4.dp))
+                            }
+                            items(checkedItems, key = { it.id }) { item ->
+                                ShoppingListItemRow(
+                                    item = item,
+                                    onToggle = { viewModel.toggleCheckOff(listId, item) },
+                                    onDelete = { deletingItemId = item.id }
+                                )
+                            }
+                        }
+
+                        item { Spacer(Modifier.height(80.dp)) }
+                    }
+                }
+            }
+        }
+    }
+
+    if (showAddItemDialog) {
+        AddShoppingItemDialog(
+            onDismiss = { showAddItemDialog = false },
+            onConfirm = { name, qty, unit ->
+                viewModel.addItem(listId, name, qty, unit)
+                showAddItemDialog = false
+            }
+        )
+    }
+
+    deletingItemId?.let { itemId ->
+        AlertDialog(
+            onDismissRequest = { deletingItemId = null },
+            title = { Text("Remove item?") },
+            text = { Text("Remove this item from the list?") },
+            confirmButton = {
+                TextButton(onClick = { viewModel.deleteItem(listId, itemId); deletingItemId = null }) {
+                    Text("Remove", color = MaterialTheme.colorScheme.error)
+                }
+            },
+            dismissButton = { TextButton(onClick = { deletingItemId = null }) { Text("Cancel") } }
+        )
+    }
+}
+
+@Composable
+fun ShoppingListItemRow(
+    item: ShoppingListItemEntity,
+    onToggle: () -> Unit,
+    onDelete: () -> Unit
+) {
+    Card(
+        modifier = Modifier.fillMaxWidth(),
+        colors = CardDefaults.cardColors(
+            containerColor = if (item.checkedOff)
+                MaterialTheme.colorScheme.surfaceVariant.copy(alpha = 0.5f)
+            else MaterialTheme.colorScheme.surface
+        )
+    ) {
+        Row(
+            modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Checkbox(
+                checked = item.checkedOff,
+                onCheckedChange = { onToggle() }
+            )
+            Column(modifier = Modifier.weight(1f)) {
+                Text(
+                    item.itemName,
+                    style = MaterialTheme.typography.bodyLarge.copy(
+                        textDecoration = if (item.checkedOff) TextDecoration.LineThrough else null
+                    ),
+                    color = if (item.checkedOff)
+                        MaterialTheme.colorScheme.onSurface.copy(alpha = 0.4f)
+                    else MaterialTheme.colorScheme.onSurface
+                )
+                Text(
+                    "${formatQty(item.quantity)} ${item.unit}",
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.5f)
+                )
+            }
+            IconButton(onClick = onDelete) {
+                Icon(
+                    Icons.Default.Close,
+                    contentDescription = "Remove",
+                    tint = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.4f)
+                )
+            }
+        }
+    }
+}
+
+fun formatQty(qty: Double): String =
+    if (qty == qty.toLong().toDouble()) qty.toLong().toString()
+    else String.format("%.2f", qty).trimEnd('0').trimEnd('.')
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun AddShoppingItemDialog(onDismiss: () -> Unit, onConfirm: (String, Double, String) -> Unit) {
+    var name by remember { mutableStateOf("") }
+    var quantityText by remember { mutableStateOf("1") }
+    var selectedUnit by remember { mutableStateOf("pieces") }
+    var unitExpanded by remember { mutableStateOf(false) }
+    val quantity = quantityText.toDoubleOrNull()
+    val isValid = name.isNotBlank() && quantity != null && quantity > 0
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Add item") },
+        text = {
+            Column(verticalArrangement = Arrangement.spacedBy(12.dp)) {
+                OutlinedTextField(
+                    value = name,
+                    onValueChange = { name = it },
+                    label = { Text("Item name") },
+                    singleLine = true,
+                    modifier = Modifier.fillMaxWidth()
+                )
+                Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                    OutlinedTextField(
+                        value = quantityText,
+                        onValueChange = { quantityText = it },
+                        label = { Text("Qty") },
+                        keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Decimal),
+                        singleLine = true,
+                        isError = quantityText.isNotEmpty() && quantity == null,
+                        modifier = Modifier.weight(1f)
+                    )
+                    ExposedDropdownMenuBox(
+                        expanded = unitExpanded,
+                        onExpandedChange = { unitExpanded = it },
+                        modifier = Modifier.weight(1.5f)
+                    ) {
+                        OutlinedTextField(
+                            value = selectedUnit,
+                            onValueChange = {},
+                            readOnly = true,
+                            label = { Text("Unit") },
+                            trailingIcon = { ExposedDropdownMenuDefaults.TrailingIcon(expanded = unitExpanded) },
+                            modifier = Modifier.menuAnchor()
+                        )
+                        ExposedDropdownMenu(
+                            expanded = unitExpanded,
+                            onDismissRequest = { unitExpanded = false }
+                        ) {
+                            ALLOWED_UNITS.forEach { unit ->
+                                DropdownMenuItem(
+                                    text = { Text(unit) },
+                                    onClick = { selectedUnit = unit; unitExpanded = false }
+                                )
+                            }
+                        }
+                    }
+                }
+            }
+        },
+        confirmButton = {
+            TextButton(
+                onClick = { if (isValid) onConfirm(name, quantity!!, selectedUnit) },
+                enabled = isValid
+            ) { Text("Add") }
+        },
+        dismissButton = { TextButton(onClick = onDismiss) { Text("Cancel") } }
+    )
+}

android/app/src/main/java/com/pantree/app/ui/screens/shopping/ShoppingListViewModel.kt

@@ -0,0 +1,148 @@
+package com.pantree.app.ui.screens.shopping
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import com.pantree.app.data.local.entity.ShoppingListEntity
+import com.pantree.app.data.local.entity.ShoppingListItemEntity
+import com.pantree.app.data.repository.ShoppingListRepository
+import com.pantree.app.util.Result
+import com.pantree.app.util.toUserMessage
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.flow.*
+import kotlinx.coroutines.launch
+import javax.inject.Inject
+
+data class ShoppingListsUiState(
+    val isLoading: Boolean = false,
+    val lists: List<ShoppingListEntity> = emptyList(),
+    val error: String? = null,
+    val actionError: String? = null,
+    val actionSuccess: String? = null
+)
+
+data class ShoppingListDetailUiState(
+    val isLoading: Boolean = false,
+    val listName: String = "",
+    val items: List<ShoppingListItemEntity> = emptyList(),
+    val error: String? = null,
+    val actionError: String? = null,
+    val actionSuccess: String? = null,
+    val addRecipesSuccess: String? = null
+)
+
+@HiltViewModel
+class ShoppingListViewModel @Inject constructor(
+    private val shoppingListRepository: ShoppingListRepository
+) : ViewModel() {
+
+    private val _listsState = MutableStateFlow(ShoppingListsUiState(isLoading = true))
+    val listsState: StateFlow<ShoppingListsUiState> = _listsState.asStateFlow()
+
+    private val _detailState = MutableStateFlow(ShoppingListDetailUiState())
+    val detailState: StateFlow<ShoppingListDetailUiState> = _detailState.asStateFlow()
+
+    init {
+        viewModelScope.launch {
+            shoppingListRepository.getLocalLists().collect { lists ->
+                _listsState.update { it.copy(lists = lists, isLoading = false) }
+            }
+        }
+        fetchLists()
+    }
+
+    fun fetchLists() {
+        viewModelScope.launch {
+            _listsState.update { it.copy(isLoading = true, error = null) }
+            when (val result = shoppingListRepository.fetchLists()) {
+                is Result.Success -> _listsState.update { it.copy(isLoading = false) }
+                is Result.Error -> _listsState.update { it.copy(isLoading = false, error = result.toUserMessage()) }
+                is Result.NetworkError -> _listsState.update { it.copy(isLoading = false) }
+            }
+        }
+    }
+
+    fun createList(name: String) {
+        viewModelScope.launch {
+            when (val result = shoppingListRepository.createList(name.trim())) {
+                is Result.Success -> _listsState.update { it.copy(actionSuccess = "\"${result.data.shoppingList.listName}\" created.") }
+                is Result.Error -> _listsState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _listsState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun deleteList(listId: String) {
+        viewModelScope.launch {
+            when (val result = shoppingListRepository.deleteList(listId)) {
+                is Result.Success -> _listsState.update { it.copy(actionSuccess = "List deleted.") }
+                is Result.Error -> _listsState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _listsState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun loadListDetail(listId: String) {
+        viewModelScope.launch {
+            _detailState.update { it.copy(isLoading = true, error = null) }
+            // Observe local items immediately
+            launch {
+                shoppingListRepository.getLocalItems(listId).collect { items ->
+                    _detailState.update { it.copy(items = items, isLoading = false) }
+                }
+            }
+            when (val result = shoppingListRepository.fetchListById(listId)) {
+                is Result.Success -> _detailState.update {
+                    it.copy(isLoading = false, listName = result.data.shoppingList.listName)
+                }
+                is Result.Error -> _detailState.update { it.copy(isLoading = false, error = result.toUserMessage()) }
+                is Result.NetworkError -> _detailState.update { it.copy(isLoading = false) }
+            }
+        }
+    }
+
+    fun addItem(listId: String, name: String, quantity: Double, unit: String) {
+        viewModelScope.launch {
+            when (val result = shoppingListRepository.addItem(listId, name.trim(), quantity, unit)) {
+                is Result.Success -> {
+                    val msg = if (result.data.merged == true)
+                        "Merged with existing ${result.data.item.itemName}."
+                    else "${result.data.item.itemName} added."
+                    _detailState.update { it.copy(actionSuccess = msg, actionError = null) }
+                }
+                is Result.Error -> _detailState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _detailState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun addRecipesToList(listId: String, recipeIds: List<String>, scaleFactor: Int) {
+        viewModelScope.launch {
+            when (val result = shoppingListRepository.addRecipesToList(listId, recipeIds, scaleFactor)) {
+                is Result.Success -> _detailState.update {
+                    it.copy(addRecipesSuccess = "Added ${result.data.recipesAdded} recipe(s). ${result.data.itemsMerged} items merged, ${result.data.itemsCreated} new.")
+                }
+                is Result.Error -> _detailState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _detailState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun toggleCheckOff(listId: String, item: ShoppingListItemEntity) {
+        viewModelScope.launch {
+            shoppingListRepository.updateItem(listId, item.id, checkedOff = !item.checkedOff)
+        }
+    }
+
+    fun deleteItem(listId: String, itemId: String) {
+        viewModelScope.launch {
+            when (val result = shoppingListRepository.deleteItem(listId, itemId)) {
+                is Result.Success -> _detailState.update { it.copy(actionSuccess = "Item removed.") }
+                is Result.Error -> _detailState.update { it.copy(actionError = result.toUserMessage()) }
+                is Result.NetworkError -> _detailState.update { it.copy(actionError = "No internet connection.") }
+            }
+        }
+    }
+
+    fun clearListsMessages() = _listsState.update { it.copy(actionError = null, actionSuccess = null) }
+    fun clearDetailMessages() = _detailState.update { it.copy(actionError = null, actionSuccess = null, addRecipesSuccess = null) }
+}

android/app/src/main/java/com/pantree/app/ui/screens/shopping/ShoppingListsScreen.kt

@@ -0,0 +1,175 @@
+package com.pantree.app.ui.screens.shopping
+
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.*
+import androidx.compose.material3.*
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.pantree.app.data.local.entity.ShoppingListEntity
+import com.pantree.app.ui.components.EmptyState
+import com.pantree.app.ui.components.ErrorState
+import com.pantree.app.ui.components.LoadingState
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun ShoppingListsScreen(
+    onListClick: (String) -> Unit,
+    onNavigateBack: () -> Unit,
+    viewModel: ShoppingListViewModel = hiltViewModel()
+) {
+    val uiState by viewModel.listsState.collectAsStateWithLifecycle()
+    var showCreateDialog by remember { mutableStateOf(false) }
+    var deletingList by remember { mutableStateOf<ShoppingListEntity?>(null) }
+    val snackbarHostState = remember { SnackbarHostState() }
+
+    LaunchedEffect(uiState.actionSuccess) {
+        uiState.actionSuccess?.let { snackbarHostState.showSnackbar(it); viewModel.clearListsMessages() }
+    }
+    LaunchedEffect(uiState.actionError) {
+        uiState.actionError?.let { snackbarHostState.showSnackbar(it); viewModel.clearListsMessages() }
+    }
+
+    Scaffold(
+        topBar = {
+            TopAppBar(
+                title = { Text("Shopping Lists") },
+                navigationIcon = {
+                    IconButton(onClick = onNavigateBack) {
+                        Icon(Icons.Default.ArrowBack, "Back", tint = MaterialTheme.colorScheme.onPrimary)
+                    }
+                },
+                colors = TopAppBarDefaults.topAppBarColors(
+                    containerColor = MaterialTheme.colorScheme.primary,
+                    titleContentColor = MaterialTheme.colorScheme.onPrimary
+                )
+            )
+        },
+        floatingActionButton = {
+            FloatingActionButton(onClick = { showCreateDialog = true }) {
+                Icon(Icons.Default.Add, "Create list")
+            }
+        },
+        snackbarHost = { SnackbarHost(snackbarHostState) }
+    ) { padding ->
+        Box(modifier = Modifier.fillMaxSize().padding(padding)) {
+            when {
+                uiState.isLoading && uiState.lists.isEmpty() -> LoadingState(message = "Loading your lists...")
+                uiState.error != null && uiState.lists.isEmpty() -> ErrorState(
+                    message = uiState.error!!,
+                    onRetry = { viewModel.fetchLists() }
+                )
+                uiState.lists.isEmpty() -> EmptyState(
+                    emoji = "\uD83D\uDED2",
+                    title = "No shopping lists yet",
+                    subtitle = "Create a list to start planning your next grocery run.",
+                    actionLabel = "Create a list",
+                    onAction = { showCreateDialog = true }
+                )
+                else -> {
+                    LazyColumn(
+                        contentPadding = PaddingValues(16.dp),
+                        verticalArrangement = Arrangement.spacedBy(8.dp)
+                    ) {
+                        items(uiState.lists, key = { it.id }) { list ->
+                            ShoppingListCard(
+                                list = list,
+                                onClick = { onListClick(list.id) },
+                                onDelete = { deletingList = list }
+                            )
+                        }
+                        item { Spacer(Modifier.height(80.dp)) }
+                    }
+                }
+            }
+        }
+    }
+
+    if (showCreateDialog) {
+        CreateListDialog(
+            onDismiss = { showCreateDialog = false },
+            onConfirm = { name -> viewModel.createList(name); showCreateDialog = false }
+        )
+    }
+
+    deletingList?.let { list ->
+        AlertDialog(
+            onDismissRequest = { deletingList = null },
+            title = { Text("Delete list?") },
+            text = { Text("\"${list.listName}\" and all its items will be permanently deleted.") },
+            confirmButton = {
+                TextButton(onClick = { viewModel.deleteList(list.id); deletingList = null }) {
+                    Text("Delete", color = MaterialTheme.colorScheme.error)
+                }
+            },
+            dismissButton = { TextButton(onClick = { deletingList = null }) { Text("Cancel") } }
+        )
+    }
+}
+
+@Composable
+fun ShoppingListCard(
+    list: ShoppingListEntity,
+    onClick: () -> Unit,
+    onDelete: () -> Unit
+) {
+    Card(modifier = Modifier.fillMaxWidth(), onClick = onClick) {
+        Row(
+            modifier = Modifier.padding(horizontal = 16.dp, vertical = 12.dp),
+            verticalAlignment = Alignment.CenterVertically
+        ) {
+            Column(modifier = Modifier.weight(1f)) {
+                Text(list.listName, style = MaterialTheme.typography.titleMedium)
+                Spacer(Modifier.height(4.dp))
+                Row(horizontalArrangement = Arrangement.spacedBy(12.dp)) {
+                    Text(
+                        "${list.itemCount} item${if (list.itemCount != 1) "s" else ""}",
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.6f)
+                    )
+                    if (list.checkedCount > 0) {
+                        Text(
+                            "${list.checkedCount} checked",
+                            style = MaterialTheme.typography.bodySmall,
+                            color = MaterialTheme.colorScheme.primary
+                        )
+                    }
+                }
+            }
+            Icon(Icons.Default.ChevronRight, contentDescription = null, tint = MaterialTheme.colorScheme.onSurface.copy(alpha = 0.4f))
+            IconButton(onClick = onDelete) {
+                Icon(Icons.Default.Delete, "Delete", tint = MaterialTheme.colorScheme.error)
+            }
+        }
+    }
+}
+
+@Composable
+fun CreateListDialog(onDismiss: () -> Unit, onConfirm: (String) -> Unit) {
+    var name by remember { mutableStateOf("") }
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("New shopping list") },
+        text = {
+            OutlinedTextField(
+                value = name,
+                onValueChange = { name = it },
+                label = { Text("List name") },
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth()
+            )
+        },
+        confirmButton = {
+            TextButton(onClick = { if (name.isNotBlank()) onConfirm(name) }, enabled = name.isNotBlank()) {
+                Text("Create")
+            }
+        },
+        dismissButton = { TextButton(onClick = onDismiss) { Text("Cancel") } }
+    )
+}

android/app/src/main/java/com/pantree/app/ui/theme/Color.kt

@@ -0,0 +1,24 @@
+package com.pantree.app.ui.theme
+
+import androidx.compose.ui.graphics.Color
+
+// Brand palette
+val PantreeGreen = Color(0xFF2D6A4F)
+val PantreeGreenLight = Color(0xFF52B788)
+val PantreeGreenDark = Color(0xFF1B4332)
+val PantreeCream = Color(0xFFF8F4EF)
+val PantreeOrange = Color(0xFFE76F51)
+val PantreeOrangeLight = Color(0xFFF4A261)
+
+// Semantic
+val SuccessGreen = Color(0xFF40916C)
+val ErrorRed = Color(0xFFD62828)
+val WarningAmber = Color(0xFFF4A261)
+val NeutralGray = Color(0xFF6B7280)
+val SurfaceWhite = Color(0xFFFFFFFF)
+val BackgroundCream = Color(0xFFF8F4EF)
+
+// Dark theme
+val PantreeGreenDarkTheme = Color(0xFF52B788)
+val SurfaceDark = Color(0xFF1C1C1E)
+val BackgroundDark = Color(0xFF121212)

android/app/src/main/java/com/pantree/app/ui/theme/Theme.kt

@@ -0,0 +1,65 @@
+package com.pantree.app.ui.theme
+
+import android.app.Activity
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.material3.lightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.SideEffect
+import androidx.compose.ui.graphics.toArgb
+import androidx.compose.ui.platform.LocalView
+import androidx.core.view.WindowCompat
+
+private val LightColorScheme = lightColorScheme(
+    primary = PantreeGreen,
+    onPrimary = SurfaceWhite,
+    primaryContainer = PantreeGreenLight,
+    onPrimaryContainer = PantreeGreenDark,
+    secondary = PantreeOrange,
+    onSecondary = SurfaceWhite,
+    secondaryContainer = PantreeOrangeLight,
+    background = BackgroundCream,
+    onBackground = PantreeGreenDark,
+    surface = SurfaceWhite,
+    onSurface = PantreeGreenDark,
+    error = ErrorRed,
+    onError = SurfaceWhite,
+    outline = NeutralGray
+)
+
+private val DarkColorScheme = darkColorScheme(
+    primary = PantreeGreenDarkTheme,
+    onPrimary = PantreeGreenDark,
+    primaryContainer = PantreeGreenDark,
+    onPrimaryContainer = PantreeGreenLight,
+    secondary = PantreeOrangeLight,
+    onSecondary = SurfaceDark,
+    background = BackgroundDark,
+    onBackground = PantreeCream,
+    surface = SurfaceDark,
+    onSurface = PantreeCream,
+    error = ErrorRed,
+    onError = SurfaceWhite
+)
+
+@Composable
+fun PantreeTheme(
+    darkTheme: Boolean = isSystemInDarkTheme(),
+    content: @Composable () -> Unit
+) {
+    val colorScheme = if (darkTheme) DarkColorScheme else LightColorScheme
+    val view = LocalView.current
+    if (!view.isInEditMode) {
+        SideEffect {
+            val window = (view.context as Activity).window
+            window.statusBarColor = colorScheme.primary.toArgb()
+            WindowCompat.getInsetsController(window, view).isAppearanceLightStatusBars = !darkTheme
+        }
+    }
+    MaterialTheme(
+        colorScheme = colorScheme,
+        typography = PantreeTypography,
+        content = content
+    )
+}

android/app/src/main/java/com/pantree/app/ui/theme/Type.kt

@@ -0,0 +1,54 @@
+package com.pantree.app.ui.theme
+
+import androidx.compose.material3.Typography
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.sp
+
+val PantreeTypography = Typography(
+    headlineLarge = TextStyle(
+        fontWeight = FontWeight.Bold,
+        fontSize = 32.sp,
+        lineHeight = 40.sp
+    ),
+    headlineMedium = TextStyle(
+        fontWeight = FontWeight.SemiBold,
+        fontSize = 24.sp,
+        lineHeight = 32.sp
+    ),
+    headlineSmall = TextStyle(
+        fontWeight = FontWeight.SemiBold,
+        fontSize = 20.sp,
+        lineHeight = 28.sp
+    ),
+    titleLarge = TextStyle(
+        fontWeight = FontWeight.SemiBold,
+        fontSize = 18.sp,
+        lineHeight = 24.sp
+    ),
+    titleMedium = TextStyle(
+        fontWeight = FontWeight.Medium,
+        fontSize = 16.sp,
+        lineHeight = 22.sp
+    ),
+    bodyLarge = TextStyle(
+        fontWeight = FontWeight.Normal,
+        fontSize = 16.sp,
+        lineHeight = 24.sp
+    ),
+    bodyMedium = TextStyle(
+        fontWeight = FontWeight.Normal,
+        fontSize = 14.sp,
+        lineHeight = 20.sp
+    ),
+    bodySmall = TextStyle(
+        fontWeight = FontWeight.Normal,
+        fontSize = 12.sp,
+        lineHeight = 16.sp
+    ),
+    labelLarge = TextStyle(
+        fontWeight = FontWeight.Medium,
+        fontSize = 14.sp,
+        lineHeight = 20.sp
+    )
+)

android/app/src/main/java/com/pantree/app/util/Result.kt

@@ -0,0 +1,58 @@
+package com.pantree.app.util
+
+import com.google.gson.Gson
+import com.pantree.app.data.model.ApiError
+import retrofit2.Response
+
+sealed class Result<out T> {
+    data class Success<T>(val data: T) : Result<T>()
+    data class Error(val code: String, val message: String, val httpStatus: Int = 0) : Result<Nothing>()
+    object NetworkError : Result<Nothing>()
+}
+
+suspend fun <T> safeApiCall(gson: Gson, call: suspend () -> Response<T>): Result<T> {
+    return try {
+        val response = call()
+        if (response.isSuccessful) {
+            val body = response.body()
+            if (body != null) {
+                Result.Success(body)
+            } else if (response.code() == 204) {
+                @Suppress("UNCHECKED_CAST")
+                Result.Success(Unit as T)
+            } else {
+                Result.Error("EMPTY_BODY", "Empty response body", response.code())
+            }
+        } else {
+            val errorBody = response.errorBody()?.string()
+            val apiError = try {
+                gson.fromJson(errorBody, ApiError::class.java)
+            } catch (e: Exception) {
+                null
+            }
+            Result.Error(
+                code = apiError?.code ?: "UNKNOWN_ERROR",
+                message = apiError?.error ?: "Something went wrong. Please try again.",
+                httpStatus = response.code()
+            )
+        }
+    } catch (e: java.io.IOException) {
+        Result.NetworkError
+    } catch (e: Exception) {
+        Result.Error("UNKNOWN_ERROR", e.message ?: "An unexpected error occurred.")
+    }
+}
+
+fun Result.Error.toUserMessage(): String = when (code) {
+    "VALIDATION_ERROR" -> message
+    "UNAUTHORIZED" -> "Your session has expired. Please sign in again."
+    "FORBIDDEN" -> message
+    "NOT_FOUND" -> "That item couldn't be found."
+    "CONFLICT" -> message
+    "DUPLICATE_ITEM" -> message
+    "ACCOUNT_PENDING_DELETION" -> message
+    "GONE" -> "This account no longer exists."
+    "INVALID_TOKEN" -> "That link has expired. Please request a new one."
+    "INVALID_GOOGLE_TOKEN" -> "Google sign-in failed. Please try again."
+    else -> "Something went wrong. Please try again."
+}

android/app/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">Pantree</string>
+</resources>

android/app/src/main/res/values/themes.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="Theme.Pantree" parent="android:Theme.Material.Light.NoActionBar" />
+</resources>

android/app/src/test/java/com/pantree/app/ui/screens/recipe/RecipeDetailScreenTest.kt

@@ -0,0 +1,25 @@
+package com.pantree.app.ui.screens.recipe
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class RecipeDetailScreenTest {
+
+    @Test
+    fun `formatQuantity whole number strips decimal`() {
+        assertEquals("2", formatQuantity(2.0))
+        assertEquals("10", formatQuantity(10.0))
+    }
+
+    @Test
+    fun `formatQuantity decimal trims trailing zeros`() {
+        assertEquals("2.5", formatQuantity(2.5))
+        assertEquals("0.25", formatQuantity(0.25))
+    }
+
+    @Test
+    fun `formatQuantity handles repeating decimal`() {
+        val result = formatQuantity(0.6666666666)
+        assertTrue(result.startsWith("0.66"))
+    }
+}

android/app/src/test/java/com/pantree/app/util/ResultTest.kt

@@ -0,0 +1,31 @@
+package com.pantree.app.util
+
+import org.junit.Assert.*
+import org.junit.Test
+
+class ResultTest {
+
+    @Test
+    fun `toUserMessage returns human message for UNAUTHORIZED`() {
+        val error = Result.Error(code = "UNAUTHORIZED", message = "raw", httpStatus = 401)
+        assertEquals("Your session has expired. Please sign in again.", error.toUserMessage())
+    }
+
+    @Test
+    fun `toUserMessage returns human message for NOT_FOUND`() {
+        val error = Result.Error(code = "NOT_FOUND", message = "raw", httpStatus = 404)
+        assertEquals("That item couldn't be found.", error.toUserMessage())
+    }
+
+    @Test
+    fun `toUserMessage passes through VALIDATION_ERROR message`() {
+        val error = Result.Error(code = "VALIDATION_ERROR", message = "Email is required", httpStatus = 400)
+        assertEquals("Email is required", error.toUserMessage())
+    }
+
+    @Test
+    fun `toUserMessage returns generic for unknown code`() {
+        val error = Result.Error(code = "SOME_WEIRD_CODE", message = "raw", httpStatus = 500)
+        assertEquals("Something went wrong. Please try again.", error.toUserMessage())
+    }
+}

android/build.gradle

@@ -0,0 +1,8 @@
+// Top-level build file
+plugins {
+    id 'com.android.application' version '8.3.0' apply false
+    id 'com.android.library' version '8.3.0' apply false
+    id 'org.jetbrains.kotlin.android' version '1.9.23' apply false
+    id 'com.google.dagger.hilt.android' version '2.51.1' apply false
+    id 'com.google.devtools.ksp' version '1.9.23-1.0.20' apply false
+}

android/settings.gradle

@@ -0,0 +1,16 @@
+pluginManagement {
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+rootProject.name = "Pantree"
+include ':app'