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/api/src/routes/library.rs

@@ -136,6 +136,11 @@ async fn list_collections(
     State(state): State<AppState>,
     CurrentUser(_user): CurrentUser,
 ) -> Result<Json<Vec<CollectionResponse>>, ApiError> {
+    if !state.media_provider.capabilities().collections {
+        return Err(ApiError::not_implemented(
+            "collections not supported by this provider",
+        ));
+    }
     let collections = state.media_provider.list_collections().await?;
     Ok(Json(collections.into_iter().map(Into::into).collect()))
 }
@@ -146,6 +151,11 @@ async fn list_series(
     CurrentUser(_user): CurrentUser,
     Query(params): Query<SeriesQuery>,
 ) -> Result<Json<Vec<SeriesResponse>>, ApiError> {
+    if !state.media_provider.capabilities().series {
+        return Err(ApiError::not_implemented(
+            "series not supported by this provider",
+        ));
+    }
     let series = state
         .media_provider
         .list_series(params.collection.as_deref())
@@ -159,6 +169,11 @@ async fn list_genres(
     CurrentUser(_user): CurrentUser,
     Query(params): Query<GenresQuery>,
 ) -> Result<Json<Vec<String>>, ApiError> {
+    if !state.media_provider.capabilities().genres {
+        return Err(ApiError::not_implemented(
+            "genres not supported by this provider",
+        ));
+    }
     let ct = parse_content_type(params.content_type.as_deref())?;
     let genres = state.media_provider.list_genres(ct.as_ref()).await?;
     Ok(Json(genres))