docs(ios): drop stale debug comments + TeamTalk refs from audio router

After the stereo-mic/A2DP debugging settled, the iOS audio code carried
leftover TeamTalk5 comparison notes, source-line citations, TEMP DIAGNOSTIC
markers, and "this was the bug" narratives that no longer help. Reworded
those to state the current rules; kept the comments that document real
constraints (the setPreferredInputNumberOfChannels(2) trap, the re-entrancy
guard, the ma_context no-session-management config).

Comment-only — no behavior change. core builds, ctest --preset dev 21/21.

clients/apple/iOS/VoiceCatiOS/AudioSessionManager.swift

@@ -16,12 +16,10 @@ final class AudioSessionManager {
     var activeMicStreamId: UInt32?
 
     /// Tracks whether WE activated the session. The session must be active whenever the
-    /// AudioEngine is running (for capture OR playback). Previously, the session was only
-    /// activated when the user joined voice (startMicStream), which meant:
-    ///   - Remote audio was silent if the user hadn't joined voice yet.
-    ///   - Leaving voice (stopMicStream) deactivated the session, killing remote audio.
-    /// Now the session is activated when any audio needs to play (remote stream started OR
-    /// user joins voice) and only deactivated when disconnecting from the server.
+    /// AudioEngine is running (for capture OR playback), so it is activated when any audio
+    /// needs to play (a remote stream started OR the user joins voice) and only deactivated
+    /// when disconnecting from the server — not when leaving voice, since the user may still
+    /// want to hear remote audio.
     private var isSessionActive = false
 
     func configure() {
@@ -78,12 +76,10 @@ final class AudioSessionManager {
         logger.info("session deactivated")
     }
 
-    /// TEMP DIAGNOSTIC (stereo-A2DP fix verification): log the full AVAudioSession state —
-    /// category, mode, options, and active route. The bug was miniaudio resetting the category
-    /// to `Record` (no output) on device open; with the core's ma_context now configured to
-    /// leave the session alone, this should report `AVAudioSessionCategoryPlayAndRecord` with
-    /// `allowBluetoothA2DP` set, and the output route should be the headphones/A2DP device —
-    /// even after the mic engine starts. Remove once verified on-device.
+    /// Log the full AVAudioSession state — category, mode, options, and active route.
+    /// Useful for diagnosing routing issues, e.g. confirming the session stays
+    /// `PlayAndRecord` with `allowBluetoothA2DP` and keeps the A2DP output route even
+    /// after the mic engine starts.
     func logSessionState(_ when: String) {
         let s = AVAudioSession.sharedInstance()
         var opts: [String] = []