fix: harden OriginOS recognition tracking

frontend/lib/shared/services/screenshot_channel.dart

@@ -95,6 +95,14 @@ class RecognitionStatus {
   final DateTime? accessibilityLastConnectedAt;
   final DateTime? accessibilityLastDisconnectedAt;
   final DateTime? recognitionProcessStartedAt;
+  final bool keepAliveExpected;
+  final bool keepAliveRunning;
+  final String? keepAliveError;
+  final bool recentsProtectionExpected;
+  final bool recentsProtectionActive;
+  final DateTime? lastRecognitionExitAt;
+  final String? lastRecognitionExitReason;
+  final bool taskCleanerRecoveryNeeded;
   final bool notificationAuthorized;
   final bool notificationConnected;
   final bool postNotificationsGranted;
@@ -116,6 +124,14 @@ class RecognitionStatus {
     this.accessibilityLastConnectedAt,
     this.accessibilityLastDisconnectedAt,
     this.recognitionProcessStartedAt,
+    this.keepAliveExpected = false,
+    this.keepAliveRunning = false,
+    this.keepAliveError,
+    this.recentsProtectionExpected = false,
+    this.recentsProtectionActive = false,
+    this.lastRecognitionExitAt,
+    this.lastRecognitionExitReason,
+    this.taskCleanerRecoveryNeeded = false,
     required this.notificationAuthorized,
     required this.notificationConnected,
     required this.postNotificationsGranted,
@@ -158,6 +174,17 @@ class RecognitionStatus {
         'accessibilityLastDisconnectedAt',
       ),
       recognitionProcessStartedAt: epochDate('recognitionProcessStartedAt'),
+      keepAliveExpected: value['keepAliveExpected'] as bool? ?? false,
+      keepAliveRunning: value['keepAliveRunning'] as bool? ?? false,
+      keepAliveError: value['keepAliveError']?.toString(),
+      recentsProtectionExpected:
+          value['recentsProtectionExpected'] as bool? ?? false,
+      recentsProtectionActive:
+          value['recentsProtectionActive'] as bool? ?? false,
+      lastRecognitionExitAt: epochDate('lastRecognitionExitAt'),
+      lastRecognitionExitReason: value['lastRecognitionExitReason']?.toString(),
+      taskCleanerRecoveryNeeded:
+          value['taskCleanerRecoveryNeeded'] as bool? ?? false,
       notificationAuthorized: value['notificationAuthorized'] as bool? ?? false,
       notificationConnected: value['notificationConnected'] as bool? ?? false,
       postNotificationsGranted:
@@ -189,6 +216,8 @@ class RecognitionStatus {
       !accessibilityConnected &&
       accessibilityConnectionState == AccessibilityConnectionState.disconnected;
 
+  bool get keepAliveNeedsRecovery => keepAliveExpected && !keepAliveRunning;
+
   String get accessibilityConnectionLabel =>
       switch (accessibilityConnectionState) {
         AccessibilityConnectionState.unauthorized => '未授权',
@@ -320,6 +349,7 @@ class SpeechEvent {
 /// Android native capabilities for screenshots, AI progress and speech.
 class ScreenshotChannel {
   static const _channel = MethodChannel('com.miaoji/screenshot');
+  static Future<RecognitionStatus>? _activeAccessibilityConnectionWait;
   static void Function(String path)? _screenshotReady;
   static void Function(String error)? _screenshotError;
   static void Function(SpeechEvent event)? _speechEvent;
@@ -472,13 +502,32 @@ class ScreenshotChannel {
   static Future<RecognitionStatus> waitForAccessibilityConnection({
     Duration timeout = const Duration(seconds: 5),
     Duration interval = const Duration(milliseconds: 500),
+  }) {
+    final active = _activeAccessibilityConnectionWait;
+    if (active != null) return active;
+    final operation = _waitForAccessibilityConnection(
+      timeout: timeout,
+      interval: interval,
+    );
+    _activeAccessibilityConnectionWait = operation;
+    return operation.whenComplete(() {
+      if (identical(_activeAccessibilityConnectionWait, operation)) {
+        _activeAccessibilityConnectionWait = null;
+      }
+    });
+  }
+
+  static Future<RecognitionStatus> _waitForAccessibilityConnection({
+    required Duration timeout,
+    required Duration interval,
   }) async {
     var status = await recognitionStatus();
     final recognitionEnabled =
         status.accessibilityEvents || status.aiScreenshot;
     if (!recognitionEnabled ||
         !status.accessibilityAuthorized ||
-        status.accessibilityConnected) {
+        status.accessibilityConnected ||
+        status.taskCleanerRecoveryNeeded) {
       return status;
     }
     final deadline = DateTime.now().add(timeout);
@@ -487,6 +536,7 @@ class ScreenshotChannel {
       status = await recognitionStatus();
       if (!status.accessibilityAuthorized ||
           status.accessibilityConnected ||
+          status.taskCleanerRecoveryNeeded ||
           !(status.accessibilityEvents || status.aiScreenshot)) {
         return status;
       }
@@ -494,6 +544,15 @@ class ScreenshotChannel {
     return status;
   }
 
+  static Future<bool> ensureRecognitionKeepAlive() async {
+    try {
+      return await _channel.invokeMethod<bool>('ensureRecognitionKeepAlive') ??
+          false;
+    } on MissingPluginException {
+      return false;
+    }
+  }
+
   static Future<bool> clearRecognitionDiagnostic() async {
     try {
       return await _channel.invokeMethod<bool>('clearRecognitionDiagnostic') ??