Tab cycles panels within a view; views switch only via F1-F4/Alt+digit

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

internal/ui/downloads.go

@@ -84,13 +84,20 @@ func newDownloadsView(app *App, sab *sabnzbd.Client, sources []arrSource, interv
 	common := func(extra map[rune]func()) func(*tcell.EventKey) *tcell.EventKey {
 		keys := map[rune]func(){
 			'r': v.refreshNow,
-			'h': v.nextPanel,
 			'p': v.togglePause,
 		}
 		for r, f := range extra {
 			keys[r] = f
 		}
 		return func(ev *tcell.EventKey) *tcell.EventKey {
+			switch ev.Key() {
+			case tcell.KeyTab:
+				v.nextPanel(1)
+				return nil
+			case tcell.KeyBacktab:
+				v.nextPanel(-1)
+				return nil
+			}
 			if ev.Key() == tcell.KeyRune {
 				if f, ok := keys[ev.Rune()]; ok {
 					f()
@@ -114,12 +121,13 @@ func newDownloadsView(app *App, sab *sabnzbd.Client, sources []arrSource, interv
 	return v
 }
 
-// nextPanel moves focus to the next panel (queue, Radarr/Sonarr queue, history).
-func (v *downloadsView) nextPanel() {
+// nextPanel moves focus to the next (dir 1) or previous (dir -1) panel:
+// queue, Radarr/Sonarr queue, history.
+func (v *downloadsView) nextPanel(dir int) {
 	cur := v.app.app.GetFocus()
 	for i, p := range v.panels {
 		if p == cur {
-			v.app.app.SetFocus(v.panels[(i+1)%len(v.panels)])
+			v.app.app.SetFocus(v.panels[(i+dir+len(v.panels))%len(v.panels)])
 			return
 		}
 	}