dispose images correctly

app/lib/features/geckoview/domain/providers/tab_state.dart

@@ -45,6 +45,24 @@ part 'tab_state.g.dart';
 
 @Riverpod(keepAlive: true)
 class TabStates extends _$TabStates {
+  /// Disposes images from a TabState to free GPU memory.
+  void _disposeTabImages(TabState tab) {
+    tab.icon?.dispose();
+    tab.thumbnail?.dispose();
+  }
+
+  /// Updates state while disposing images from removed tabs.
+  void _updateState(Map<String, TabState> newState) {
+    // Find and dispose images from tabs that are being removed
+    for (final tabId in state.keys) {
+      if (!newState.containsKey(tabId)) {
+        _disposeTabImages(state[tabId]!);
+      }
+    }
+
+    state = newState;
+  }
+
   Future<void> _onTabContentStateChange(TabContentState contentState) async {
     final current = await patchedState(contentState.id);
 
@@ -71,7 +89,7 @@ class TabStates extends _$TabStates {
       isLoading: contentState.isLoading,
     );
 
-    state = {...state}..[contentState.id] = newState;
+    _updateState({...state}..[contentState.id] = newState);
 
     if (newState.isFinishedLoading) {
       ref
@@ -104,6 +122,9 @@ class TabStates extends _$TabStates {
   Future<void> _onIconChange(IconChangeEvent event) async {
     final IconChangeEvent(:tabId, :bytes) = event;
 
+    // Dispose old icon before replacing
+    state[tabId]?.icon?.dispose();
+
     final image = await bytes.mapNotNull((bytes) => tryDecodeImage(bytes));
 
     final current = state[tabId] ?? TabState.$default(tabId);
@@ -113,6 +134,9 @@ class TabStates extends _$TabStates {
   Future<void> _onThumbnailChange(ThumbnailEvent event) async {
     final ThumbnailEvent(:tabId, :bytes) = event;
 
+    // Dispose old thumbnail before replacing
+    state[tabId]?.thumbnail?.dispose();
+
     final image = await bytes.mapNotNull((bytes) => tryDecodeImage(bytes));
 
     final current = state[tabId] ?? TabState.$default(tabId);
@@ -244,6 +268,12 @@ class TabStates extends _$TabStates {
     );
 
     ref.onDispose(() async {
+      // Dispose all images from all tabs
+      for (final tab in state.values) {
+        _disposeTabImages(tab);
+      }
+
+      // Cancel all stream subscriptions
       for (final sub in subscriptions) {
         await sub.cancel();
       }

app/lib/features/geckoview/domain/providers/tab_state.g.dart

@@ -41,7 +41,7 @@ final class TabStatesProvider
   }
 }
 
-String _$tabStatesHash() => r'cd73ea6ea479f2708a2c9e5ca86054c9d2464116';
+String _$tabStatesHash() => r'f2e6920017b3f46944d85254c09c54779eb89eb3';
 
 abstract class _$TabStates extends $Notifier<Map<String, TabState>> {
   Map<String, TabState> build();

app/lib/features/geckoview/domain/providers/web_extensions_state.dart

@@ -61,6 +61,8 @@ class WebExtensionsState extends _$WebExtensionsState {
     } else {
       if (state.containsKey(extensionId)) {
         state = {...state}..remove(extensionId);
+        // Dispose the cached image when extension is removed
+        _imageCache.remove(extensionId)?.dispose();
       }
     }
   }
@@ -71,13 +73,14 @@ class WebExtensionsState extends _$WebExtensionsState {
     final image = await tryDecodeImage(bytes);
 
     if (image != null) {
-      if (_imageCache[extensionId] != image) {
-        _imageCache[extensionId] = image;
+      // Dispose old image before replacing
+      _imageCache[extensionId]?.dispose();
 
-        if (state.containsKey(extensionId)) {
-          state = {...state}
-            ..[extensionId] = state[extensionId]!.copyWith.icon(image);
-        }
+      _imageCache[extensionId] = image;
+
+      if (state.containsKey(extensionId)) {
+        state = {...state}
+          ..[extensionId] = state[extensionId]!.copyWith.icon(image);
       }
     }
   }
@@ -106,6 +109,13 @@ class WebExtensionsState extends _$WebExtensionsState {
     };
 
     ref.onDispose(() async {
+      // Dispose all cached images
+      for (final image in _imageCache.values) {
+        image.dispose();
+      }
+      _imageCache.clear();
+
+      // Cancel all stream subscriptions
       for (final sub in subscriptions) {
         await sub.cancel();
       }

app/lib/features/geckoview/domain/providers/web_extensions_state.g.dart

@@ -62,7 +62,7 @@ final class WebExtensionsStateProvider
 }
 
 String _$webExtensionsStateHash() =>
-    r'6fb44ab543250f2b2554e410ee749fdd035cd4e7';
+    r'd7147f419889386f8cf526aed3318839ac22d893';
 
 final class WebExtensionsStateFamily extends $Family
     with