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.