feat(button,media_player): Pair ADB carries entity_category CONFIG (t30 G11) + BrowseMediaSource domain parameter at root and children (t30 G18, 2026-05-20 blog contract); stubs/tests pin both

custom_components/nvidia_shield/media_player.py

@@ -941,6 +941,8 @@ class NvidiaShieldMediaPlayer(MediaPlayerEntity):
         )
 
         app_map = self._entry.options.get(CONF_APP_NAME_MAP) or DEFAULT_APP_DIRECTORY
+        # G18 (2026-05-20 blog): BrowseMediaSource must carry the domain
+        # parameter so the frontend can attribute the media tree.
         children = [
             BrowseMediaSource(
                 title=name,
@@ -949,6 +951,7 @@ class NvidiaShieldMediaPlayer(MediaPlayerEntity):
                 media_content_id=pkg,
                 can_play=True,
                 can_expand=False,
+                domain=DOMAIN,
             )
             for pkg, name in app_map.items()
         ]
@@ -960,6 +963,7 @@ class NvidiaShieldMediaPlayer(MediaPlayerEntity):
             can_play=False,
             can_expand=True,
             children=children,
+            domain=DOMAIN,
         )
 
     # ── play_media (§7): channel digits, app/url launch ──