Channel numbers on the remote pad, EPG column redesign, calmer overlay

- Number keys type the stable channel number (position in Alle Sender,
  shown identically in every view) with a live feedback badge; commits
  after a short pause or as soon as no longer number can match.
- EPG cell is a left-aligned column with a fixed leading edge: title +
  time range, progress under the title, next line only when it differs;
  placeholder programmes (kein Programm / no information) count as no
  EPG data. Star hidden in the favorites view.
- Player overlay: no LIVE dot (reads as recording) and no status word
  while playing; state text only for paused/buffering/error.
- Settings pill gets a resting surface so it reads as a target.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/src/main/java/dev/castarr/tv/AppState.kt

@@ -42,6 +42,9 @@ class AppState(
         private set
     private var lastNowTitle: String? = null
 
+    /** Digits typed on the remote's number pad (channel switching). */
+    var digitBuffer by mutableStateOf("")
+
     /** Bumped on every interaction with the visible overlay to restart the
      * auto-hide timer. */
     var overlayPing by mutableLongStateOf(0L)