Initial commit: Phase 1 – Projektstruktur, DB-Schema, Core-API

- FastAPI-Backend mit vollständiger ABS v2.x API-Kompatibilität
- SQLAlchemy-Models: User, Library, LibraryItem, BookFile, Chapter,
  Podcast, PodcastEpisode, MediaProgress, Bookmark, PlaybackSession
- Auth: JWT-Login (/login, /logout, /api/authorize)
- Library + Items Endpoints inkl. camelCase ABS-Response-Format
- HLS-Streaming via FFmpeg (POST /api/items/:id/play, Session-Sync)
- Me/Progress Endpoints + Lesezeichen
- User-Management + Server-Settings (Admin)
- Library-Scanner (MP3/WAV Discovery, Hintergrund-Task)
- File Watcher (watchdog, 30s Debounce)
- Matching-Skelett (MusicBrainz, OpenLibrary, Google Books – Phase 5)
- Docker-Setup: backend (Python 3.12+FFmpeg), frontend (React/Vite),
  nginx Reverse-Proxy auf Port 3000
- setup.sh: Installiert Docker auf Debian/Ubuntu, richtet .env ein

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/models/__init__.py

@@ -0,0 +1,12 @@
+from .user import User
+from .library import Library
+from .media_item import LibraryItem, BookFile, Chapter
+from .podcast import Podcast, PodcastEpisode
+from .progress import MediaProgress, Bookmark
+from .session import PlaybackSession, ServerSetting, ScanJob
+
+__all__ = [
+    "User", "Library", "LibraryItem", "BookFile", "Chapter",
+    "Podcast", "PodcastEpisode", "MediaProgress", "Bookmark",
+    "PlaybackSession", "ServerSetting", "ScanJob",
+]