gpodder: dont use yt-dlp for channel management

hosts/common/programs/gpodder/settings.nix

@@ -17,7 +17,11 @@
   ];
   extensions.youtube-dl = {
     embed_subtitles = false;
-    manage_channel = true;
+    # manage_channel = true: uses `yt-dlp` to fetch the list of episodes for a channel.
+    # manage_downloads = true: uses `yt-dlp` to download each individual episode.
+    # XXX(2025-07-30): `manage_channel = false` otherwise yt-dlp hangs the refresh operation (it gets stuck on age verification?)
+    #   `manage_downloads = true` because only yt-dlp can handle DRM'd video; native gpodder cannot.
+    manage_channel = false;
     manage_downloads = true;
   };
   limit.bandwidth.enabled = false;