chore: comment cleanup pass ahead of open-sourcing

Removes leftover debug scaffolding (stray Console.WriteLine/NSLog traces,
dead nick_buf_ptr, a no-op --print-config flag now implemented for real),
fixes stale/misleading comments (channel passwords are no longer a "future
M5+" feature, a wrong cross-reference, a stale TlsContext::close() mention,
an incomplete BanRecord::subject_type doc, and a smoke test pointing at a
build/m1-dev preset that no longer exists), strips internal M1-M5 milestone
jargon from comments now that the roadmap is done, trims comments that just
restated the following line, and consolidates a few "why" explanations that
were duplicated 2-3 times in the same file.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

clients/apple/iOS/VoiceCatiOS/IOSAudioRouter.swift

@@ -163,13 +163,8 @@ final class IOSAudioRouter: ObservableObject {
     /// burns CPU and cycles the audio session on/off (the "glitching" bug).
     private var isApplyingConfiguration = false
 
-    /// Last `overrideOutputAudioPort` value we successfully applied (`.none` or `.speaker`),
-    /// so `applyA2dpSpeakerFallback` can skip a redundant `overrideOutputAudioPort` call.
-    /// That call fires a `.override` route-change notification on every invocation, and on
-    /// an AirPods disconnect the fallback is invoked once per `recoverAudio()` — which
-    /// itself fires on every non-skipped route change — so without this guard the override
-    /// call and the route-change handler ping-pong: the AirPods-disconnect reinitialize
-    /// loop (each iteration also rebuilds the AVAudioEngine via reconfigure()).
+    /// Last `overrideOutputAudioPort` value we successfully applied (`.none` or `.speaker`).
+    /// See `applyA2dpSpeakerFallback`'s doc comment for why this cache exists.
     /// `nil` = "unknown / assume not applied" — reset at the top of `applyConfiguration()`
     /// because `setCategory` can reset the override out from under us, and on first run.
     private var lastAppliedOutputOverride: AVAudioSession.PortOverride?
@@ -382,13 +377,8 @@ final class IOSAudioRouter: ObservableObject {
 
         // 3. Input & mic-capsule configuration.
         if captureChannels == .stereo {
-            // Stereo: enable the built-in mic's .stereo polar pattern AND anchor the input
-            // route explicitly via setPreferredInput + setInputDataSource. With HFP disabled
-            // the system routes input to the built-in mic, but without the explicit
-            // preferred-input anchor the route can collapse during the mode switch
-            // (.voiceChat → .default) and the output dies. The channel count is carried by the
-            // engine's mic tap + vc_set_capture_channels, NOT via
-            // setPreferredInputNumberOfChannels(2) — that call collapses the A2DP output route.
+            // See configureStereoCapture's doc comment for the full stereo-capture recipe
+            // and why each step is necessary.
             configureStereoCapture(session: session)
         } else if let portId = selectedInputPortId, !portId.isEmpty,
                   let port = session.availableInputs?.first(where: { $0.uid == portId }) {
@@ -434,8 +424,6 @@ final class IOSAudioRouter: ObservableObject {
         do {
             try builtIn.setPreferredDataSource(stereoSource)
             try stereoSource.setPreferredPolarPattern(.stereo)
-            // Anchor the input route explicitly; without it the route can collapse during
-            // the mode switch (.voiceChat → .default) and the A2DP output dies.
             try session.setPreferredInput(builtIn)
             // Commit the data source at the session level. setPreferredDataSource alone only
             // sets the port-level preference; setInputDataSource makes it the active source.
@@ -697,8 +685,6 @@ final class IOSAudioRouter: ObservableObject {
         }
         let desired: AVAudioSession.PortOverride = hasExternalOutput ? .none : .speaker
         if desired == lastAppliedOutputOverride {
-            // Already in the desired state — calling overrideOutputAudioPort again would just
-            // fire a redundant `.override` route-change notification (the loop driver).
             logger.debug("A2DP fallback — desired=\(self.overrideLabel(desired)) already applied, skipping")
             return
         }