Add media browser feature with UI improvements

- Refactored index.html: Split into separate HTML (309 lines), CSS (908 lines), and JS (1,286 lines) files
- Implemented media browser with folder configuration, recursive navigation, and thumbnail display
- Added metadata extraction using mutagen library (title, artist, album, duration, bitrate, codec)
- Implemented thumbnail generation and caching with SHA256 hash-based keys and LRU eviction
- Added platform-specific file playback (os.startfile on Windows, xdg-open on Linux, open on macOS)
- Implemented path validation security to prevent directory traversal attacks
- Added smooth thumbnail loading with fade-in animation and loading spinner
- Added i18n support for browser (English and Russian)
- Updated dependencies: mutagen>=1.47.0, pillow>=10.0.0
- Added comprehensive media browser documentation to README

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

media_server/main.py

@@ -15,7 +15,7 @@ from fastapi.staticfiles import StaticFiles
 from . import __version__
 from .auth import get_token_label, token_label_var
 from .config import settings, generate_default_config, get_config_dir
-from .routes import audio_router, callbacks_router, health_router, media_router, scripts_router
+from .routes import audio_router, browser_router, callbacks_router, health_router, media_router, scripts_router
 from .services import get_media_controller
 from .services.websocket_manager import ws_manager
 
@@ -110,6 +110,7 @@ def create_app() -> FastAPI:
 
     # Register routers
     app.include_router(audio_router)
+    app.include_router(browser_router)
     app.include_router(callbacks_router)
     app.include_router(health_router)
     app.include_router(media_router)