fix: address codex review findings on probe/watchdog fallback

- a probe or raster-stall failure record now also downgrades sessions
  that are already running: main_set_local_option broadcasts the
  fallback for failed-* health writes, which also closes the hole where
  the watchdog's idempotence guard no-oped after the probe had already
  written the record
- probe success requires a frame timing newer than the first push:
  'consumed' advances inside the plugin callback before the GL/Metal
  upload, so a raster thread hanging in the driver no longer counts as
  a pass (and cannot clear a previous failure)
- watchdog failures are tagged with the failing backend
  (failed-watchdog-rgba/gpu); the rgba-only probe clears only the rgba
  class, so a working pixel-buffer path can no longer re-enable a
  broken D3D shared-handle path every launch
- the watchdog pauses while the session's window is hidden (new
  session_set_render_visible FFI wired to the window minimize/restore
  events): a display registered in a minimized window no longer records
  a false global failure; observation now counts pushes within the
  window rather than since registration
- probe failure verdicts additionally require a resumed lifecycle,
  matching the raster-stall monitor
- linux plugin: deferred-unref grace lengthened to 10s (no raster-side
  completion barrier exists; documented as heuristic), ref bumped

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

flutter/lib/desktop/widgets/tabbar_widget.dart

@@ -11,6 +11,7 @@ import 'package:flutter_hbb/consts.dart';
 import 'package:flutter_hbb/desktop/pages/remote_page.dart';
 import 'package:flutter_hbb/desktop/pages/view_camera_page.dart';
 import 'package:flutter_hbb/main.dart';
+import 'package:flutter_hbb/models/model.dart';
 import 'package:flutter_hbb/models/platform_model.dart';
 import 'package:flutter_hbb/models/state_model.dart';
 import 'package:get/get.dart';
@@ -388,6 +389,7 @@ class _DesktopTabState extends State<DesktopTab>
   void onWindowMinimize() {
     stateGlobal.setMinimized(true);
     stateGlobal.setMaximized(false);
+    _updateSessionsRenderVisible(false);
     super.onWindowMinimize();
   }
 
@@ -395,6 +397,7 @@ class _DesktopTabState extends State<DesktopTab>
   void onWindowMaximize() {
     stateGlobal.setMinimized(false);
     _setMaximized(true);
+    _updateSessionsRenderVisible(true);
     super.onWindowMaximize();
   }
 
@@ -402,6 +405,7 @@ class _DesktopTabState extends State<DesktopTab>
   void onWindowUnmaximize() {
     stateGlobal.setMinimized(false);
     _setMaximized(false);
+    _updateSessionsRenderVisible(true);
     super.onWindowUnmaximize();
   }
 
@@ -409,9 +413,26 @@ class _DesktopTabState extends State<DesktopTab>
   void onWindowRestore() {
     // A plain restore (no maximize involved) must clear the minimized flag.
     stateGlobal.setMinimized(false);
+    _updateSessionsRenderVisible(true);
     super.onWindowRestore();
   }
 
+  // A hidden window composites nothing; pause the Rust-side texture watchdog
+  // for its sessions so it cannot record a false failure.
+  void _updateSessionsRenderVisible(bool visible) {
+    if (tabType != DesktopTabType.remoteScreen &&
+        tabType != DesktopTabType.viewCamera) {
+      return;
+    }
+    for (final tab in controller.state.value.tabs) {
+      try {
+        final ffi = Get.find<FFI>(tag: tab.key);
+        bind.sessionSetRenderVisible(
+            sessionId: ffi.sessionId, visible: visible);
+      } catch (_) {}
+    }
+  }
+
   _saveFrame({bool? flush}) async {
     try {
       if (tabType == DesktopTabType.main) {

flutter/lib/desktop/widgets/texture_render_probe.dart

@@ -32,6 +32,7 @@ class _TextureRenderProbeState extends State<TextureRenderProbe> {
   bool _sawTimings = false;
   bool _wasEffectiveOn = false;
   DateTime? _lastTimings;
+  DateTime? _firstPush;
 
   @override
   void initState() {
@@ -82,15 +83,31 @@ class _TextureRenderProbeState extends State<TextureRenderProbe> {
     setState(() => _textureId = id);
     _timer = Timer.periodic(const Duration(milliseconds: 100), (_) {
       _ticks += 1;
+      _firstPush ??= DateTime.now();
       bind.mainPushTextureProbeFrame(ptr: _ptr);
-      if (bind.mainGetTextureProbeConsumed(ptr: _ptr) > 0) {
+      final consumed = bind.mainGetTextureProbeConsumed(ptr: _ptr) > 0;
+      // "Consumed" advances inside the plugin callback, before the GL/Metal
+      // upload; only a frame timing after the push proves a completed frame.
+      final frameCompleted = consumed &&
+          _lastTimings != null &&
+          _lastTimings!.isAfter(_firstPush!);
+      if (frameCompleted) {
         _finish(true);
       } else if (_ticks >= 10) {
+        if (consumed) {
+          _finish(null);
+          return;
+        }
         // Only a window that is visibly compositing can prove a failure.
+        final lifecycle = SchedulerBinding.instance.lifecycleState;
+        final active =
+            lifecycle == null || lifecycle == AppLifecycleState.resumed;
         final timingsFresh = _lastTimings != null &&
             DateTime.now().difference(_lastTimings!) <
                 const Duration(milliseconds: 1500);
-        _finish(!stateGlobal.isMinimized && timingsFresh ? false : null);
+        _finish(!stateGlobal.isMinimized && active && timingsFresh
+            ? false
+            : null);
       }
     });
   }
@@ -102,9 +119,12 @@ class _TextureRenderProbeState extends State<TextureRenderProbe> {
     if (ok != null) {
       final old = bind.mainGetLocalOption(key: kOptionTextureRenderHealth);
       if (ok) {
-        // A 1x1 probe pass disproves the black-texture class, not a
-        // raster-stall under load; that record only clears via the toggle.
-        if (old != 'ok' && !old.startsWith('failed-raster-stall')) {
+        // This rgba probe disproves only the rgba black-texture class: gpu
+        // failures and raster stalls clear via the option toggle alone.
+        final clearable = old.isEmpty ||
+            old.startsWith('failed-probe') ||
+            old.startsWith('failed-watchdog-rgba');
+        if (clearable) {
           bind.mainSetLocalOption(key: kOptionTextureRenderHealth, value: 'ok');
         }
       } else if (!old.startsWith('failed')) {

flutter/lib/web/bridge.dart

@@ -1462,6 +1462,9 @@ class RustdeskImpl {
       required int ptr,
       dynamic hint}) {}
 
+  void sessionSetRenderVisible(
+      {required UuidValue sessionId, required bool visible, dynamic hint}) {}
+
   bool mainTextureRenderProbeSupported({dynamic hint}) {
     return false;
   }

flutter/pubspec.lock

@@ -1298,8 +1298,8 @@ packages:
     dependency: "direct main"
     description:
       path: "."
-      ref: "7932bf9c7f64b34b3d136ff07acd7e30dd279c34"
-      resolved-ref: "7932bf9c7f64b34b3d136ff07acd7e30dd279c34"
+      ref: "883326ddd4fb2af1484bf873b4ea856a0ac440bc"
+      resolved-ref: "883326ddd4fb2af1484bf873b4ea856a0ac440bc"
       url: "https://github.com/rustdesk-org/flutter_texture_rgba_renderer"
     source: git
     version: "0.0.16"

flutter/pubspec.yaml

@@ -88,7 +88,7 @@ dependencies:
   texture_rgba_renderer:
     git:
       url: https://github.com/rustdesk-org/flutter_texture_rgba_renderer
-      ref: 7932bf9c7f64b34b3d136ff07acd7e30dd279c34
+      ref: 883326ddd4fb2af1484bf873b4ea856a0ac440bc
   percent_indicator: ^4.2.2
   dropdown_button2: ^2.0.0
   flutter_gpu_texture_renderer: