Details pane: director and cast from Trakt

With a Trakt client ID, the details of a movie or series show the
director(s) or creators and up to 8 cast members with their roles below
the plot, in every view. The title is found on Trakt by its TMDb/TVDB
(else IMDb) id, then its people are read. Casts are cached and, like
posters, only loaded once the selection rests.

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

internal/ui/configapply.go

@@ -33,6 +33,10 @@ func (a *App) applyConfig(c *config.Config) {
 	}
 	if old.Trakt.ClientID != c.Trakt.ClientID {
 		a.trakt.Reconfigure(c.Trakt.ClientID)
+		a.people = newPeopleCache()
+		for _, p := range a.panes {
+			p.castKey = "" // ask again the next time a title is shown
+		}
 	}
 	if old.Trakt.ClientID != c.Trakt.ClientID || old.Radarr.Service != c.Radarr.Service || old.Sonarr.Service != c.Sonarr.Service {
 		for _, v := range a.searches {