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/services/file_watcher.py

@@ -0,0 +1,94 @@
+import asyncio
+import logging
+import uuid
+from pathlib import Path
+from watchdog.observers import Observer
+from watchdog.events import FileSystemEventHandler, FileCreatedEvent, FileMovedEvent
+from ..database import AsyncSessionLocal
+from ..models.library import Library
+from ..models.session import ScanJob
+from sqlalchemy import select
+
+logger = logging.getLogger(__name__)
+
+AUDIO_EXTENSIONS = {".mp3", ".wav", ".m4a", ".flac", ".ogg", ".aac", ".m4b", ".opus"}
+
+_observer: Observer | None = None
+_scan_debounce: dict[str, asyncio.TimerHandle] = {}
+
+
+class AudioFileHandler(FileSystemEventHandler):
+    def __init__(self, library_id: str, loop: asyncio.AbstractEventLoop):
+        self.library_id = library_id
+        self.loop = loop
+
+    def _schedule_scan(self):
+        key = self.library_id
+        if key in _scan_debounce:
+            _scan_debounce[key].cancel()
+        handle = self.loop.call_later(
+            30.0,  # 30s Debounce — nicht bei jeder Datei sofort scannen
+            lambda: asyncio.run_coroutine_threadsafe(
+                _trigger_scan(self.library_id), self.loop
+            ),
+        )
+        _scan_debounce[key] = handle
+
+    def on_created(self, event):
+        if not event.is_directory:
+            ext = Path(event.src_path).suffix.lower()
+            if ext in AUDIO_EXTENSIONS:
+                logger.info(f"Neue Audiodatei erkannt: {event.src_path}")
+                self._schedule_scan()
+
+    def on_moved(self, event):
+        if not event.is_directory:
+            ext = Path(event.dest_path).suffix.lower()
+            if ext in AUDIO_EXTENSIONS:
+                logger.info(f"Audiodatei verschoben: {event.dest_path}")
+                self._schedule_scan()
+
+
+async def _trigger_scan(library_id: str):
+    from ..services.scanner import scan_library_task
+    async with AsyncSessionLocal() as db:
+        job = ScanJob(
+            id=str(uuid.uuid4()),
+            library_id=library_id,
+            status="queued",
+        )
+        db.add(job)
+        await db.commit()
+        await db.refresh(job)
+    asyncio.create_task(scan_library_task(library_id, job.id))
+
+
+async def start_file_watcher():
+    global _observer
+    loop = asyncio.get_event_loop()
+
+    async with AsyncSessionLocal() as db:
+        result = await db.execute(select(Library))
+        libraries = result.scalars().all()
+
+    observer = Observer()
+    for lib in libraries:
+        for folder_info in (lib.folders or []):
+            folder_path = folder_info.get("fullPath", folder_info.get("full_path", ""))
+            if folder_path and Path(folder_path).exists():
+                handler = AudioFileHandler(lib.id, loop)
+                observer.schedule(handler, folder_path, recursive=True)
+                logger.info(f"Watching: {folder_path} (Library: {lib.name})")
+
+    observer.start()
+    _observer = observer
+    logger.info("File Watcher gestartet.")
+
+
+def stop_file_watcher():
+    global _observer
+    if _observer:
+        _observer.stop()
+        _observer.join()
+        _observer = None
+        logger.info("File Watcher gestoppt.")