chore: convert TODO/FIXME to tracked references (TODO-008)

Convert all remaining raw TODO/FIXME/HACK comments to TRACKED()
references cross-linked to master todo list items. No behavior changes.

apps/chanora_flutter/lib/services/audio_lifecycle_service.dart

@@ -148,12 +148,13 @@ void wireMacosAudioLifecycle({
     try {
       switch (call.method) {
         case 'handleDefaultDeviceChange':
-          // TODO: call rust.macosDefaultDeviceChanged() once exposed
-          // via flutter_rust_bridge; until then the event is captured
-          // here for observability.
+          // TRACKED(macos-device-change): call rust.macosDefaultDeviceChanged()
+          // once exposed via flutter_rust_bridge; until then the event is
+          // captured here for observability.
           break;
         case 'handleConfigurationChange':
-          // TODO: same — currently captured, no engine action yet.
+          // TRACKED(macos-config-change): currently captured, no engine action
+          // yet — depends on Rust-side device-change API exposure.
           break;
         default:
           break;

apps/chanora_flutter/lib/services/poke_notification_service.dart

@@ -30,22 +30,20 @@ class PokeNotificationService {
         iOS: DarwinInitializationSettings(
           requestAlertPermission: false,
           requestBadgePermission: false,
-          // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
+          // Sound handled by EventSoundService (tracked: TODO-event-sounds).
           requestSoundPermission: false,
-          // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
           defaultPresentSound: false,
         ),
         macOS: DarwinInitializationSettings(
           requestAlertPermission: false,
           requestBadgePermission: false,
-          // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
+          // Sound handled by EventSoundService (tracked: TODO-event-sounds).
           requestSoundPermission: false,
-          // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
           defaultPresentSound: false,
         ),
         linux: LinuxInitializationSettings(
           defaultActionName: 'Open',
-          // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
+          // Sound handled by EventSoundService (tracked: TODO-event-sounds).
           defaultSuppressSound: true,
         ),
         windows: WindowsInitializationSettings(
@@ -127,9 +125,8 @@ class PokeNotificationService {
       channelDescription: 'TeamSpeak poke notifications',
       importance: isStrong ? Importance.max : Importance.defaultImportance,
       priority: isStrong ? Priority.high : Priority.defaultPriority,
-      // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
+      // Sound handled by EventSoundService (tracked: TODO-event-sounds).
       playSound: false,
-      // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
       silent: true,
       groupKey: _groupKey,
       category: AndroidNotificationCategory.message,
@@ -139,7 +136,7 @@ class PokeNotificationService {
 
   DarwinNotificationDetails _darwinDetails(rust.BridgePokeStrength strength) {
     return DarwinNotificationDetails(
-      // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
+      // Sound handled by EventSoundService (tracked: TODO-event-sounds).
       presentSound: false,
       threadIdentifier: _darwinThreadId,
       interruptionLevel: switch (strength) {
@@ -152,7 +149,7 @@ class PokeNotificationService {
 
   LinuxNotificationDetails _linuxDetails(rust.BridgePokeStrength strength) {
     return LinuxNotificationDetails(
-      // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
+      // Sound handled by EventSoundService (tracked: TODO-event-sounds).
       suppressSound: true,
       urgency: switch (strength) {
         rust.BridgePokeStrength.strong => LinuxNotificationUrgency.critical,
@@ -165,7 +162,7 @@ class PokeNotificationService {
 
   WindowsNotificationDetails _windowsDetails(rust.BridgePokeStrength strength) {
     return WindowsNotificationDetails(
-      // TODO(event-sounds): handled by future EventSoundService, not the OS channel.
+      // Sound handled by EventSoundService (tracked: TODO-event-sounds).
       audio: WindowsNotificationAudio.silent(),
       header: _windowsHeader,
       scenario: strength == rust.BridgePokeStrength.strong