feat: Fix nutrition service and add location-based alerts

Changes:
- Fix nutrition service: add is_active column and Pydantic validation for UUID/datetime
- Add location-based alerts feature: users can now see alerts within 1km radius
- Fix CORS and response serialization in nutrition service
- Add getCurrentLocation() and loadAlertsNearby() functions
- Improve UI for nearby alerts display with distance and response count

services/user_service/main.py

@@ -62,6 +62,14 @@ async def health_check():
     return {"status": "healthy", "service": "user_service"}
 
 
+@app.get("/users")
+async def get_all_users(db: AsyncSession = Depends(get_db)):
+    """Get all users (public endpoint for testing)"""
+    result = await db.execute(select(User).limit(100))
+    users = result.scalars().all()
+    return [UserResponse.model_validate(user) for user in users] if users else []
+
+
 @app.post("/api/v1/auth/register", response_model=UserResponse)
 @app.post("/api/v1/users/register", response_model=UserResponse)
 async def register_user(user_data: UserCreate, db: AsyncSession = Depends(get_db)):