Initial commit: Happy Up monorepo through Sprint 5.

Document-driven MVP with FastAPI backend, Vue H5, WeChat mini shell, product demo, and Docker dev stack.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/app/middleware.py

@@ -0,0 +1,11 @@
+from starlette.middleware.base import BaseHTTPMiddleware
+from starlette.requests import Request
+from uuid import uuid4
+
+
+class RequestContextMiddleware(BaseHTTPMiddleware):
+    async def dispatch(self, request: Request, call_next):
+        request.state.request_id = request.headers.get("X-Request-Id") or uuid4().hex
+        response = await call_next(request)
+        response.headers["X-Request-Id"] = request.state.request_id
+        return response