Add source field, UI filter, and import mapping

Introduce a 'source' property across types and API models, include it in convertApiToMedia, and add a Source input to AddMediaView. Add source-based filtering in BrowseView (dropdown + tag icon) and ensure Clear Filters resets source. Update playnite, stashapp, and xbvr importers to set source conditionally using a new SOURCE_CATEGORY_MAPPING constant (added to types) so sources are only applied for appropriate media categories.

src/lib/playniteImporter.ts

@@ -1,5 +1,8 @@
 const BASE_URL = import.meta.env.VITE_API_URL;
 
+// Import the source mapping
+import { SOURCE_CATEGORY_MAPPING } from '@/types';
+
 export interface PlayniteConfig {
   ip: string;
   apiToken: string;
@@ -241,7 +244,7 @@ export async function importFromPlaynite(
           series: game.series ? [game.series] : [],
           ageRatings: game.ageRatings || [],
           regions: game.regions || [],
-          source: game.source || null,
+          source: SOURCE_CATEGORY_MAPPING['playnite']?.includes('Games') ? (game.source || 'playnite') : null,
           gameId: game.id,
           pluginId: null,
           completionStatus: game.completionStatus || 'Not Played',