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-frontend/lib/api.ts

@@ -142,6 +142,11 @@ export const api = {
     },
   },
 
+  files: {
+    rescan: (token: string) =>
+      request<{ items_found: number }>("/files/rescan", { method: "POST", token }),
+  },
+
   schedule: {
     generate: (channelId: string, token: string) =>
       request<ScheduleResponse>(`/channels/${channelId}/schedule`, {