Add empty test level and Unreal MCP tooling

- L_TestFlight: empty, zero-gravity level for Phase 0 flight testing,
  set as editor/game default map.
- Enable UnrealMCPython + Python Editor Script Plugin, third-party
  MCP plugin (GenOrca/unreal-mcp v2.2.0) giving direct editor control
  (actors, blueprints, levels, materials, etc.) alongside Epic's
  built-in Unreal MCP plugin.
- Vendor the mcp-server Python source used to bridge to the plugin.
- .mcp.json intentionally gitignored (machine-specific absolute paths).

mcp-server/tests/test_core.py

@@ -0,0 +1,45 @@
+# Copyright (c) 2025 GenOrca. All Rights Reserved.
+
+"""Unit tests for the TCP response unwrapping (offline, no Unreal)."""
+
+from unreal_mcp.core import _unwrap_result
+
+
+def test_unwraps_action_dict_from_result_string():
+    wire = {
+        "success": True,  # python-exec success, NOT action success
+        "message": "Python command executed successfully.",
+        "result": '{"success": true, "actor_label": "PointLight_2"}',
+    }
+    out = _unwrap_result(wire)
+    assert out == {"success": True, "actor_label": "PointLight_2"}
+
+
+def test_unwrapped_inner_failure_is_surfaced():
+    """Action failure (inner success=False) must survive unwrapping as data."""
+    wire = {
+        "success": True,  # python ran fine...
+        "result": '{"success": false, "message": "Actor not found"}',
+    }
+    out = _unwrap_result(wire)
+    assert out["success"] is False
+    assert out["message"] == "Actor not found"
+
+
+def test_unwraps_list_result():
+    wire = {"success": True, "result": '[1, 2, 3]'}
+    assert _unwrap_result(wire) == [1, 2, 3]
+
+
+def test_non_json_result_returns_original():
+    wire = {"success": True, "result": "not json at all"}
+    assert _unwrap_result(wire) == wire
+
+
+def test_missing_result_returns_original():
+    wire = {"success": True, "message": "ok"}
+    assert _unwrap_result(wire) == wire
+
+
+def test_non_dict_passthrough():
+    assert _unwrap_result("raw") == "raw"