sweep ClideTappable across 15 files, remove 267 lines

23 StatefulWidget+State hover pairs converted to StatelessWidget
using ClideTappable(builder: (ctx, hovered, _) => ...). Covers
app.dart (5), welcome (2), claude session host (2), column hat (2),
spine (1), pane chrome (1), tab bar (1), decisions (1), tickets (1),
graph (1), pql panel (1), backlinks (1), file tree (2), git panel (1),
git status (1). Only EditorDragHandle and ClidePalette excluded
(drag/keyboard behavior beyond hover+tap).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lib/widgets/src/clide_tab_bar.dart

@@ -1,5 +1,6 @@
 import 'package:clide/kernel/src/theme/controller.dart';
 import 'package:clide/widgets/src/clide_icon.dart';
+import 'package:clide/widgets/src/clide_tappable.dart';
 import 'package:clide/widgets/src/clide_text.dart';
 import 'package:flutter/widgets.dart';
 
@@ -59,51 +60,35 @@ class ClideTabBar extends StatelessWidget {
   }
 }
 
-class _Tab extends StatefulWidget {
+class _Tab extends StatelessWidget {
   const _Tab({required this.item, required this.active, required this.onTap});
 
   final ClideTabItem item;
   final bool active;
   final VoidCallback onTap;
 
-  @override
-  State<_Tab> createState() => _TabState();
-}
-
-class _TabState extends State<_Tab> {
-  bool _hovered = false;
-
   @override
   Widget build(BuildContext context) {
     final tokens = ClideTheme.of(context).surface;
-    final bg = widget.active
-        ? tokens.tabActive
-        : (_hovered ? tokens.tabInactive : tokens.tabInactive);
-    final fg = widget.active
-        ? tokens.tabActiveForeground
-        : tokens.tabInactiveForeground;
+    final fg = active ? tokens.tabActiveForeground : tokens.tabInactiveForeground;
 
     return Semantics(
       button: true,
-      selected: widget.active,
-      label: widget.item.title,
-      onTap: widget.onTap,
+      selected: active,
+      label: item.title,
+      onTap: onTap,
       excludeSemantics: true,
-      child: MouseRegion(
-        cursor: SystemMouseCursors.click,
-        onEnter: (_) => setState(() => _hovered = true),
-        onExit: (_) => setState(() => _hovered = false),
-        child: GestureDetector(
-          onTap: widget.onTap,
-          child: Container(
+      child: ClideTappable(
+        onTap: onTap,
+        builder: (context, hovered, _) {
+          final bg = active ? tokens.tabActive : tokens.tabInactive;
+          return Container(
             padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
             decoration: BoxDecoration(
               color: bg,
               border: Border(
                 bottom: BorderSide(
-                  color: widget.active
-                      ? tokens.tabActiveBorder
-                      : const Color(0x00000000),
+                  color: active ? tokens.tabActiveBorder : const Color(0x00000000),
                   width: 2,
                 ),
               ),
@@ -111,15 +96,15 @@ class _TabState extends State<_Tab> {
             child: Row(
               mainAxisSize: MainAxisSize.min,
               children: [
-                if (widget.item.icon != null) ...[
-                  ClideIcon(widget.item.icon!, size: 12, color: fg),
+                if (item.icon != null) ...[
+                  ClideIcon(item.icon!, size: 12, color: fg),
                   const SizedBox(width: 6),
                 ],
-                ClideText(widget.item.title, color: fg),
+                ClideText(item.title, color: fg),
               ],
             ),
-          ),
-        ),
+          );
+        },
       ),
     );
   }