fix: prevent premature route resolution before initial auth check completes

[Copilot]

On page load/refresh, AuthProvider initializes with signed: false while the async session check runs in App's useEffect. The router renders immediately with the unauthenticated config, redirecting logged-in users away from /home before the check resolves.

Changes

• AuthContext.ts: Added loading: boolean to AuthContextData interface
• AuthProvider.tsx: Added loading state (default true); moved the initial checkCurrentAuthUser call here (from App.tsx) in a mount-only useEffect; sets loading = false via .catch().finally() after the check settles
• App.tsx: Reads loading from context; suppresses RouterProvider until loading is false; removes the now-redundant checkCurrentAuthUser useEffect
• authContextMock.ts: Added loading: false to the test mock
• AuthProvider.test.tsx: Added tests asserting loading transitions to false after mount (both with and without a valid token)

// AuthProvider — loading cleared regardless of auth outcome
useEffect(() => {
  checkCurrentAuthUser(window.location.pathname)
    .catch(e => console.error(e))
    .finally(() => setLoading(false));
}, []);

// App — router withheld until auth state is known
{!loading && <RouterProvider router={browserRouter} />}

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• download.cypress.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node dist/index.js --exec install (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)