feat: implement backend API for Pantree Phase 1 MVP

- Project setup: package.json, tsconfig.json, jest.config.js, .env.example
- Config: env.ts, constants.ts (ALLOWED_UNITS, bcrypt rounds, JWT, deletion windows)
- DB: Knex connection, knexfile, migrations 001-006 (users, password_reset_tokens,
  pantry_items, recipes+recipe_ingredients, shopping_lists+items, deleted_records)
- Seeds: 10 seeded recipes with full ingredient lists
- Middleware: JWT authMiddleware (validates token + user existence), errorHandler
- Utils: Pino logger, JWT sign helper, Zod validators for all request shapes
- Services: authService (signup/signin/google/pwd-reset/soft-delete/restore),
  pantryService (CRUD + case-insensitive duplicate guard),
  recipeService (browse+filter+scale), shoppingListService (CRUD+merge logic),
  syncService (delta sync + tombstone cleanup), emailService (SendGrid)
- Routes: /v1/auth, /v1/pantry, /v1/recipes, /v1/shopping-lists, /v1/sync
- App: Express factory (createApp), server entry point
- Jobs: node-cron daily hard-delete + tombstone cleanup
- Tests: validators, utils, auth, pantry, recipes, shopping lists, sync

package.json

@@ -0,0 +1,49 @@
+{
+  "name": "pantree-backend",
+  "version": "1.0.0",
+  "description": "Pantree API Server",
+  "main": "dist/server.js",
+  "scripts": {
+    "build": "tsc",
+    "start": "node dist/server.js",
+    "dev": "ts-node-dev --respawn --transpile-only src/server.ts",
+    "test": "jest --runInBand --forceExit",
+    "test:coverage": "jest --runInBand --forceExit --coverage",
+    "migrate": "knex migrate:latest --knexfile src/db/knexfile.ts",
+    "migrate:rollback": "knex migrate:rollback --knexfile src/db/knexfile.ts",
+    "seed": "knex seed:run --knexfile src/db/knexfile.ts"
+  },
+  "dependencies": {
+    "@sendgrid/mail": "^8.1.0",
+    "bcrypt": "^5.1.1",
+    "cors": "^2.8.5",
+    "dotenv": "^16.4.5",
+    "express": "^4.19.2",
+    "google-auth-library": "^9.10.0",
+    "jsonwebtoken": "^9.0.2",
+    "knex": "^3.1.0",
+    "node-cron": "^3.0.3",
+    "pg": "^8.11.5",
+    "pino": "^9.1.0",
+    "pino-http": "^10.1.0",
+    "uuid": "^9.0.1",
+    "zod": "^3.23.8"
+  },
+  "devDependencies": {
+    "@types/bcrypt": "^5.0.2",
+    "@types/cors": "^2.8.17",
+    "@types/express": "^4.17.21",
+    "@types/jest": "^29.5.12",
+    "@types/jsonwebtoken": "^9.0.6",
+    "@types/node": "^20.12.12",
+    "@types/node-cron": "^3.0.11",
+    "@types/supertest": "^6.0.2",
+    "@types/uuid": "^9.0.8",
+    "jest": "^29.7.0",
+    "supertest": "^7.0.0",
+    "ts-jest": "^29.1.4",
+    "ts-node": "^10.9.2",
+    "ts-node-dev": "^2.0.0",
+    "typescript": "^5.4.5"
+  }
+}