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/builtin/decisions/src/decisions_view.dart

@@ -102,31 +102,22 @@ class _DecisionEntry {
       );
 }
 
-class _DecisionRow extends StatefulWidget {
+class _DecisionRow extends StatelessWidget {
   const _DecisionRow({required this.entry, required this.tokens});
   final _DecisionEntry entry;
   final SurfaceTokens tokens;
 
-  @override
-  State<_DecisionRow> createState() => _DecisionRowState();
-}
-
-class _DecisionRowState extends State<_DecisionRow> {
-  bool _hovered = false;
-
   @override
   Widget build(BuildContext context) {
-    return MouseRegion(
-      onEnter: (_) => setState(() => _hovered = true),
-      onExit: (_) => setState(() => _hovered = false),
-      child: Container(
-        color: _hovered ? widget.tokens.listItemHoverBackground : null,
+    return ClideTappable(
+      builder: (context, hovered, _) => Container(
+        color: hovered ? tokens.listItemHoverBackground : null,
         padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 4),
         child: Row(
           children: [
-            ClideText(widget.entry.id, color: widget.tokens.globalTextMuted, fontSize: 12),
+            ClideText(entry.id, color: tokens.globalTextMuted, fontSize: 12),
             const SizedBox(width: 8),
-            Expanded(child: ClideText(widget.entry.title, fontSize: 13)),
+            Expanded(child: ClideText(entry.title, fontSize: 13)),
           ],
         ),
       ),