make Claude sidebar sub-tabs keyboard-activatable

The Activity / Team / Config sub-tabs were built on a raw GestureDetector,
so Tab traversal skipped them and Enter/Space did nothing — a gap against
the repo's a11y contract. Switch to ClideTappable (focusable, Enter/Space
activates) wrapped in button + selected semantics, and add a test that
drives the switch via ActivateIntent rather than a pointer tap.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -58,6 +58,11 @@ heading, and (b) bumping `pubspec.yaml` `version:` in the same commit.
 
 ### Fixed
 
+- The Claude sidebar's Activity / Team / Config sub-tabs are now keyboard-
+  activatable: they were pointer-only (raw `GestureDetector`), so Tab traversal
+  skipped them and Enter/Space did nothing. They now use `ClideTappable`
+  (focusable, Enter/Space → activate) and carry button + selected semantics.
+  (T-182)
 - The default keymap is no longer silently disabled at startup: `default.yaml`
   bound Tab/Shift+Tab to undefined `focus.next`/`focus.previous` intents, which
   made the loader drop the entire preset (palette, quick-open, find-in-files,

lib/builtin/claude/src/claude_meta_sidebar.dart

@@ -1229,11 +1229,15 @@ class _TabStrip extends StatelessWidget {
           for (final t in SidebarTab.values)
             Padding(
               padding: const EdgeInsets.only(right: 16),
-              child: GestureDetector(
+              child: Semantics(
+                button: true,
+                selected: t == current,
+                label: _label(t),
+                excludeSemantics: true,
                 onTap: () => onPick(t),
-                child: MouseRegion(
-                  cursor: SystemMouseCursors.click,
-                  child: Container(
+                child: ClideTappable(
+                  onTap: () => onPick(t),
+                  builder: (ctx, hovered, _) => Container(
                     padding: const EdgeInsets.only(bottom: 3),
                     decoration: BoxDecoration(
                       border: Border(
@@ -1246,7 +1250,7 @@ class _TabStrip extends StatelessWidget {
                     child: ClideText(
                       _label(t),
                       fontSize: clideFontSmall,
-                      color: t == current ? tokens.globalForeground : tokens.globalTextMuted,
+                      color: t == current || hovered ? tokens.globalForeground : tokens.globalTextMuted,
                     ),
                   ),
                 ),

test/builtin/claude/claude_meta_sidebar_test.dart

@@ -11,7 +11,7 @@ import 'package:clide/builtin/claude/src/transcript_publisher.dart';
 import 'package:clide/builtin/claude/src/transcript_reader.dart';
 import 'package:clide/kernel/kernel.dart';
 import 'package:flutter/services.dart' show LogicalKeyboardKey;
-import 'package:flutter/widgets.dart' show EditableText, SizedBox, Semantics;
+import 'package:flutter/widgets.dart' show ActivateIntent, Actions, EditableText, SizedBox, Semantics;
 import 'package:flutter_test/flutter_test.dart';
 
 import '../../helpers/kernel_fixture.dart';
@@ -106,6 +106,20 @@ void main() {
     expect(find.text('TODAY'), findsOneWidget);
   });
 
+  testWidgets('a sub-tab is keyboard-activatable, not pointer-only (T-182)', (tester) async {
+    await tester.pumpWidget(harness(f, sidebar(stats: stats)));
+    await tester.pumpAndSettle();
+
+    // The tab wraps its label in a ClideTappable, so the keymap's Enter/Space
+    // → ActivateIntent reaches it. Dispatch ActivateIntent through the real
+    // Actions path (what KeymapService does) — no pointer tap — and the body
+    // switches. Mirrors test/widgets/src/clide_tappable_test.dart.
+    Actions.invoke(tester.element(find.text('Team')), const ActivateIntent());
+    await tester.pump();
+    expect(find.text('No team active.'), findsOneWidget);
+    expect(find.text('TODAY'), findsNothing);
+  });
+
   testWidgets('Config tab renders the settings table over ClaudeConfig', (tester) async {
     final dir = Directory.systemTemp.createTempSync('cfg');
     addTearDown(() => dir.deleteSync(recursive: true));