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>

frontend/Dockerfile

@@ -0,0 +1,12 @@
+FROM node:20-alpine AS builder
+
+WORKDIR /app
+COPY package.json package-lock.json* ./
+RUN npm ci
+COPY . .
+RUN npm run build
+
+FROM nginx:1.25-alpine
+COPY --from=builder /app/dist /usr/share/nginx/html
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+EXPOSE 80