Preparing the App for Deployment

We're preparing the frontend for production deployment to Cloud Run.
In frontend/app.js, the backend URL is hardcoded as http://localhost:8000
in two places. Both need to become relative URLs so the same code works
locally AND on Cloud Run.

1. Inside apiFetch: change
   fetch(`http://localhost:8000${url}`, ...)
   to
   fetch(url, ...)

2. Inside handleLoginSubmit (which does NOT use apiFetch, the login
   form calls fetch directly): change
   fetch('http://localhost:8000/api/auth/login', ...)
   to
   fetch('/api/auth/login', ...)

Show me the diff before applying. Also scan the file and tell me if
there are any OTHER localhost references (comments, debug logs,
anywhere) that I might have missed.

-    const response = await fetch('http://localhost:8000/api/auth/login', {
+    const response = await fetch('/api/auth/login', {

-  const response = await fetch(`http://localhost:8000${url}`, { ...options, headers });
+  const response = await fetch(url, { ...options, headers });

We need FastAPI to serve our frontend as static files so the entire
app runs from a single origin in production.

In backend/app/main.py (NOT backend/main.py, that's just a stub):

1. Add an import at the top:
   from fastapi.staticfiles import StaticFiles

2. AFTER both router includes (auth_router and tasks_router), add a
   catch-all static files mount. The directory must be "../frontend"
   because when we deploy via Docker the WORKDIR will be /app/backend
   and the frontend folder gets copied to /app/frontend (one level up).

   app.mount("/", StaticFiles(directory="../frontend", html=True), name="static")

Critical: the mount MUST come AFTER both routers. FastAPI checks routes
in registration order. If the catch-all static mount comes first, it
will intercept every request including /api/* and break the API.

Show me the diff. Confirm the mount is positioned after both routers.
Do not touch any existing code. Only add the import and the mount.

from fastapi.staticfiles import StaticFiles

# ... app creation and CORS ...

app.include_router(auth_router)
app.include_router(tasks_router)

# Must come AFTER the API routers, or it would swallow /api/* requests
app.mount("/", StaticFiles(directory="../frontend", html=True), name="static")

cd backend
uv run uvicorn app.main:app --port 8080