feat(ios,p0): iOS P0 platform, audio fixes, channel UX

apps/chanora_flutter/lib/widgets/voice_bar.dart

@@ -183,9 +183,7 @@ class VoiceBar extends StatelessWidget {
                 const Spacer(),
                 IconButton(
                   tooltip: l10n.voiceOutputMuteLabel,
-                  icon: Icon(
-                    outputMuted ? Icons.headset_off : Icons.headset,
-                  ),
+                  icon: Icon(outputMuted ? Icons.headset_off : Icons.headset),
                   isSelected: outputMuted,
                   selectedIcon: const Icon(Icons.headset_off),
                   onPressed: onToggleOutputMute,
@@ -274,13 +272,11 @@ class VoiceBar extends StatelessWidget {
             // (single configuration entry point — see the comment
             // on `onConfigure`).
             //
-            // Hidden on touch-only mobile hosts (iOS / iPadOS /
-            // Android) because the capability story there is always
-            // "L0Focused via on-screen button" and that's already
-            // visually obvious from the PTT button being on the
-            // bar. Showing a degraded-capability badge there would
-            // be redundant + confusing.
-            if (isPtt && !_isTouchOnlyPttHost)
+            // Still shown on touch-only mobile hosts because iOS P0
+            // acceptance requires an explicit `L0Focused` badge and
+            // explanation that global hotkeys are not available in
+            // the iOS sandbox.
+            if (isPtt)
               PttCapabilityBadge(
                 level: pttLevel,
                 backendId: pttBackendId,