Trakt lists: keep the Radarr/Sonarr lookups of their titles on disk

Library membership is asked every time via movie?tmdbId= / series?tvdbId=;
only the lookups of titles not in the library are stored (3 days).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/ui/app.go

@@ -37,7 +37,8 @@ type App struct {
 	theme        theme         // the colors in use
 	trakt        *trakt.Client // trending, most watched and anticipated lists, casts
 	people       *peopleCache  // casts loaded from Trakt
-	disk         *diskCache    // posters and casts kept between runs
+	disk         *diskCache    // posters, casts and lookups kept between runs
+	lookups      *lookupStore  // Radarr/Sonarr lookups of Trakt list titles
 	// Called (on the UI goroutine) a moment after a release was grabbed.
 	afterGrab []func()
 	// The Movies and Series views, to refresh their Trakt lists.
@@ -188,8 +189,9 @@ func New(cfg *config.Config) *App {
 	if u := os.Getenv("ARR_TUI_TRAKT_URL"); u != "" {
 		a.trakt.SetBaseURL(u) // another Trakt API, for development (dev/screenshots)
 	}
-	movies := newSearchView(a, radarrBackend{radarrClient})
-	series := newSearchView(a, sonarrBackend{sonarrClient})
+	a.lookups = newLookupStore(a.disk)
+	movies := newSearchView(a, radarrBackend{radarrClient, a.lookups})
+	series := newSearchView(a, sonarrBackend{sonarrClient, a.lookups})
 	a.searches = []*searchView{movies, series}
 	a.views = []view{
 		{key: '1', name: "Movies", body: movies.root, onShow: movies.activate, hints: searchHints},
@@ -463,6 +465,7 @@ func (a *App) Run() error {
 		if a.people.dirty { // casts fetched in the last seconds
 			_ = a.disk.savePeople(a.peopleSnapshot())
 		}
+		_ = a.lookups.save()
 	}()
 	go a.disk.prunePosters()
 	// The screen draws through the theme (see themedScreen).