feat: fix auth, provider health checks, search, and redesign UI

- Fix register/login: dict-style access on UserTable ORM objects
- Fix HTMX auth: inject JWT token in all HTMX request headers
- Fix FS7 search: use DLE AJAX endpoint /engine/ajax/search.php
- Fix ZT search: use ?p=series&search=QUERY (not DLE format)
- Fix provider health: load hardcoded providers + domain manager
- Add self.id to all anime/series providers
- Redesign homepage: Netflix-style horizontal scroll cards (.hc)
- Redesign search results: grouped by title, poster + synopsis + 3 buttons
- Add Télécharger dropdown: season download + episode picker
- Fix navbar CSS: restore .tabs flex layout, remove orphan rules
- Fix HTMX spinner: remove inline display:none, use CSS indicator
- Add AGENTS.md files across project for developer documentation

app/routers/AGENTS.md

@@ -0,0 +1,37 @@
+# Routers (app/routers/)
+
+## OVERVIEW
+11 FastAPI APIRouter modules, each owning a URL prefix. All registered in `main.py:118-144`.
+
+## WHERE TO LOOK
+
+| Router | File | Prefix | Purpose |
+|--------|------|--------|---------|
+| root_router | `router_root.py` | `/`, `/web` | Index page, web UI |
+| auth_router | `router_auth.py` | `/api/auth` | Register, login, JWT tokens |
+| downloads_router | `router_downloads.py` | `/api/download` | Task CRUD, pause/resume, file serve |
+| anime_router | `router_anime.py` | `/api/anime`, `/api/series` | Search, metadata, episodes, season download |
+| favorites_router | `router_favorites.py` | `/api/favorites` | Favorites toggle, list |
+| recommendations_router | `router_recommendations.py` | `/api/recommendations`, `/api/releases` | Personalized + latest releases |
+| watchlist_router | `router_watchlist.py` | `/api/watchlist` | Watchlist CRUD, scheduler, auto-download |
+| sonarr_router | `router_sonarr.py` | `/api/sonarr`, `/api/webhook/sonarr` | Webhook receiver, mappings |
+| player_router | `router_player.py` | `/player`, `/watch` | Video player pages |
+| static_router | `router_static.py` | `/static`, `/video` | Static files, video streaming (Range) |
+| settings_router | `router_settings.py` | `/api/settings` | User app settings |
+
+## CONVENTIONS
+
+**Adding endpoints**: Identify the correct router by URL prefix → add to that file → import in `app/routers/__init__.py` (if new router) → register in `main.py`.
+
+**Shared dependencies** (via FastAPI `Depends`):
+- `download_manager: DownloadManager = Depends(lambda: download_manager)` — singleton from main.py
+- `current_user: User = Depends(get_current_user_from_token)` — JWT auth
+- `templates: Jinja2Templates = Depends(lambda: templates)` — Jinja2 renderer
+
+**Router registration** in `main.py` uses `app.include_router(router)`. Tags set per-router for OpenAPI.
+
+## ANTI-PATTERNS
+
+- Do NOT create a new router for a single endpoint — add to existing matching router
+- Do NOT use `Depends()` with direct module imports that create circular references
+- Do NOT duplicate URL prefixes across routers