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/calendar.go

@@ -15,6 +15,7 @@ import (
 	"git.stinnesbeck.com/nils/arr-tui/internal/arr"
 	"git.stinnesbeck.com/nils/arr-tui/internal/radarr"
 	"git.stinnesbeck.com/nils/arr-tui/internal/sonarr"
+	"git.stinnesbeck.com/nils/arr-tui/internal/trakt"
 )
 
 const (
@@ -134,7 +135,7 @@ func episodeEntry(e sonarr.Episode, from, to time.Time, cover coverRef, now time
 	return calEntry{
 		day: day, at: at, title: series, label: tview.Escape(series), sub: sub,
 		have: e.HasFile, monitored: e.Monitored, missing: e.Monitored && !e.HasFile && aired,
-		details: detailText{head: head, plot: tview.Escape(overview)}, cover: cover,
+		details: detailText{head: head, plot: tview.Escape(overview), people: episodeSeriesRef(e)}, cover: cover,
 		episodeID: e.ID,
 	}, true
 }
@@ -467,3 +468,11 @@ func (v *calendarView) search() {
 		})
 	}()
 }
+
+// episodeSeriesRef names the series of a calendar episode for its cast.
+func episodeSeriesRef(e sonarr.Episode) trakt.Ref {
+	if e.Series == nil {
+		return trakt.Ref{}
+	}
+	return seriesRef(*e.Series)
+}