Adds MobileHeader with hamburger button (left-aligned) that opens a
slide-in sidebar drawer on mobile. Desktop layout is unchanged. All
hardcoded multi-column grids updated with responsive Tailwind breakpoints.
Co-Authored-By: Jack Levy
- User model with email/hashed_password/is_admin/notification_prefs
- JWT auth: POST /api/auth/register, /login, /me
- First registered user auto-promoted to admin
- Migration 0005: users table + user_id FK on follows (clears global follows)
- Follows, dashboard, settings, admin endpoints all require authentication
- Admin endpoints (settings writes, celery triggers) require is_admin
- Frontend: login/register pages, Zustand auth store (localStorage persist)
- AuthGuard component gates all app routes, shows app shell only when authed
- Sidebar shows user email + logout; Admin nav link visible to admins only
- Admin panel (/settings): user list with delete + promote/demote, LLM config,
data source settings, and manual celery controls
Authored-By: Jack Levy
