chore(audio-rooms): hide drawer entry in release builds

Mirrors the Chess drawer entry pattern — `if (isDebug)` gates the
row. Audio rooms' Nostr surface (presence, hand-raise, chat) works,
but without the WebTransport audio backend the entry would bait
release-build users into a room they can't actually listen to.

One-line filter at the call site in DrawerContent.ListContent:

  val feedsItems = if (isDebug) DrawerFeedsItems
                   else DrawerFeedsItems.filter { it != NavBarItem.AUDIO_ROOMS }
  CatalogSection(..., feedsItems, ...)

Catalog entry + route + screen wiring all stay, so debug builds still
see it and the Nostr feature continues to be exercisable. When
`QuicWebTransportFactory.connect()` stops throwing NotImplemented the
two lines go away.

https://claude.ai/code/session_013nVLALALKaHVgHm9u5Cg8D

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/drawer/DrawerContent.kt

@@ -545,7 +545,12 @@ fun ListContent(
     Column(modifier) {
         CatalogSection(R.string.drawer_section_navigate, DrawerNavigateItems, accountViewModel, nav)
         CatalogSection(R.string.drawer_section_you, DrawerYouItems, accountViewModel, nav)
-        CatalogSection(R.string.drawer_section_feeds, DrawerFeedsItems, accountViewModel, nav)
+        // Audio rooms are debug-only while the WebTransport audio backend is
+        // unimplemented (see docs/plans/2026-04-22-pure-kotlin-quic-webtransport-plan.md).
+        // The Nostr-side of the feature (presence, hand-raise, chat) works, but
+        // without audio playback the entry is confusing to release-build users.
+        val feedsItems = if (isDebug) DrawerFeedsItems else DrawerFeedsItems.filter { it != NavBarItem.AUDIO_ROOMS }
+        CatalogSection(R.string.drawer_section_feeds, feedsItems, accountViewModel, nav)
 
         CollapsibleSection(title = R.string.drawer_section_create) {
             NavigationRow(