feat: add local files provider with indexing and rescan functionality

- Implemented LocalFilesProvider to manage local video files.
- Added LocalIndex for in-memory and SQLite-backed indexing of video files.
- Introduced scanning functionality to detect video files and extract metadata.
- Added API endpoints for listing collections, genres, and series based on provider capabilities.
- Enhanced existing routes to check for provider capabilities before processing requests.
- Updated frontend to utilize provider capabilities for conditional rendering of UI elements.
- Implemented rescan functionality to refresh the local files index.
- Added database migration for local files index schema.

k-tv-backend/infra/src/local_files/mod.rs

@@ -0,0 +1,8 @@
+pub mod config;
+pub mod index;
+pub mod provider;
+pub mod scanner;
+
+pub use config::LocalFilesConfig;
+pub use index::LocalIndex;
+pub use provider::{LocalFilesProvider, decode_stream_id};