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>

nginx/nginx.conf

@@ -0,0 +1,51 @@
+worker_processes auto;
+error_log /var/log/nginx/error.log warn;
+
+events {
+    worker_connections 1024;
+}
+
+http {
+    include       /etc/nginx/mime.types;
+    default_type  application/octet-stream;
+    sendfile      on;
+    keepalive_timeout 65;
+    client_max_body_size 100M;
+
+    upstream backend {
+        server backend:8000;
+    }
+
+    upstream frontend {
+        server frontend:80;
+    }
+
+    server {
+        listen 80;
+
+        # API, HLS-Streams, Auth
+        location ~ ^/(api|hls|login|logout|ping)(/.*)?$ {
+            proxy_pass http://backend;
+            proxy_set_header Host $host;
+            proxy_set_header X-Real-IP $remote_addr;
+            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+            proxy_read_timeout 300s;
+            # HLS streaming: disable buffering
+            proxy_buffering off;
+        }
+
+        # Cover images / static media served by backend
+        location /covers/ {
+            proxy_pass http://backend;
+            proxy_set_header Host $host;
+            expires 7d;
+            add_header Cache-Control "public";
+        }
+
+        # Frontend (React SPA)
+        location / {
+            proxy_pass http://frontend;
+            proxy_set_header Host $host;
+        }
+    }
+}