perf: isolate focus and media rebuilds

test/focus/input_mode_tracker_test.dart

@@ -0,0 +1,54 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:plezy/focus/input_mode_tracker.dart';
+import 'package:plezy/services/gamepad_service.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  testWidgets('one-shot reads do not subscribe to input-mode changes', (tester) async {
+    var listeningBuilds = 0;
+    var oneShotBuilds = 0;
+    InputMode? listeningMode;
+    InputMode? oneShotMode;
+
+    await tester.pumpWidget(
+      InputModeTracker(
+        child: Directionality(
+          textDirection: TextDirection.ltr,
+          child: Row(
+            children: [
+              Builder(
+                builder: (context) {
+                  listeningBuilds++;
+                  listeningMode = InputModeTracker.of(context);
+                  return const SizedBox.shrink();
+                },
+              ),
+              Builder(
+                builder: (context) {
+                  oneShotBuilds++;
+                  oneShotMode = InputModeTracker.of(context, listen: false);
+                  return const SizedBox.shrink();
+                },
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+
+    expect(listeningMode, InputMode.pointer);
+    expect(oneShotMode, InputMode.pointer);
+    expect(listeningBuilds, 1);
+    expect(oneShotBuilds, 1);
+
+    GamepadService.onGamepadInput!.call();
+    await tester.pump();
+
+    expect(listeningMode, InputMode.keyboard);
+    expect(listeningBuilds, 2);
+    expect(oneShotMode, InputMode.pointer);
+    expect(oneShotBuilds, 1);
+  });
+}

test/screens/downloads/sync_rules_screen_test.dart

@@ -89,9 +89,13 @@ class _FakeConnectionRegistry extends ConnectionRegistry {
   _FakeConnectionRegistry(super.db, this.connections);
 
   final List<Connection> connections;
+  int watchCalls = 0;
 
   @override
-  Stream<List<Connection>> watchConnections() => Stream.value(connections);
+  Stream<List<Connection>> watchConnections() {
+    watchCalls++;
+    return Stream.value(connections);
+  }
 }
 
 void main() {
@@ -102,7 +106,7 @@ void main() {
   late DownloadManagerService downloadManager;
   late MultiServerManager serverManager;
   MultiServerProvider? multiServerProvider;
-  late ConnectionRegistry connectionRegistry;
+  late _FakeConnectionRegistry connectionRegistry;
   late List<Connection> connections;
 
   setUp(() async {
@@ -251,6 +255,18 @@ void main() {
     expect(find.text('No sync rules'), findsOneWidget);
   });
 
+  testWidgets('provider rebuilds reuse the connection stream subscription', (tester) async {
+    multiServerProvider = MultiServerProvider(serverManager, DataAggregationService(serverManager));
+    await insertRule(ServerId('orphan-srv'), '76672');
+    await pumpScreen(tester);
+
+    expect(connectionRegistry.watchCalls, 1);
+    await downloadProvider.updateSyncRuleCount(downloadProvider.syncRules.keys.single, 6);
+    await tester.pump();
+
+    expect(connectionRegistry.watchCalls, 1);
+  });
+
   testWidgets('does not autofocus the first sync rule in pointer mode', (tester) async {
     multiServerProvider = MultiServerProvider(serverManager, DataAggregationService(serverManager));
     await insertRule(ServerId('orphan-srv'), '76672');

test/widgets/side_navigation_rail_test.dart

@@ -4,6 +4,7 @@ import 'package:plezy/media/ids.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:material_symbols_icons/symbols.dart';
 import 'package:plezy/i18n/strings.g.dart';
 import 'package:plezy/media/media_backend.dart';
 import 'package:plezy/media/media_kind.dart';
@@ -516,4 +517,41 @@ void main() {
 
     expect(selectedLibraryKey, hiddenServerALibrary.globalKey);
   });
+
+  testWidgets('rail item focus repaints locally without rebuilding its parent', (tester) async {
+    final focusNode = FocusNode();
+    addTearDown(focusNode.dispose);
+    var parentBuilds = 0;
+
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: ThemeData(extensions: const [_testTokens]),
+        home: Scaffold(
+          body: Builder(
+            builder: (context) {
+              parentBuilds++;
+              return NavigationRailItem(
+                icon: Symbols.home_rounded,
+                label: const Text('Home'),
+                isSelected: false,
+                onTap: () {},
+                focusNode: focusNode,
+              );
+            },
+          ),
+        ),
+      ),
+    );
+
+    final item = find.byType(NavigationRailItem);
+    expect(_railItemDecoration(tester, item)?.color, isNull);
+    expect(parentBuilds, 1);
+
+    focusNode.requestFocus();
+    await tester.pump();
+
+    expect(focusNode.hasFocus, isTrue);
+    expect(_railItemDecoration(tester, item)?.color, isNotNull);
+    expect(parentBuilds, 1);
+  });
 }