extend ClideTappable with press/longpress, retrofit button + rail

ClideTappable builder now receives (context, hovered, pressed).
Optional onLongPress and onPressChanged callbacks. ClideButton
is now a StatelessWidget wrapping ClideTappable. ClideIconRail
refactored — _RailButton uses ClideTappable with tooltip.
ClideTooltip positions smart (above when near screen bottom).

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

lib/widgets/src/clide_button.dart

@@ -1,10 +1,11 @@
 import 'package:clide/kernel/src/theme/controller.dart';
+import 'package:clide/widgets/src/clide_tappable.dart';
 import 'package:clide/widgets/src/clide_text.dart';
 import 'package:flutter/widgets.dart';
 
 enum ClideButtonVariant { normal, primary, subtle }
 
-class ClideButton extends StatefulWidget {
+class ClideButton extends StatelessWidget {
   const ClideButton({
     super.key,
     required this.label,
@@ -13,92 +14,66 @@ class ClideButton extends StatefulWidget {
     this.padding = const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
     this.semanticLabel,
     this.semanticHint,
+    this.tooltip,
   });
 
   final String label;
   final VoidCallback? onPressed;
   final ClideButtonVariant variant;
   final EdgeInsetsGeometry padding;
-
-  /// Overrides [label] for screen readers (use when the visible label is
-  /// an icon-only glyph or a noun that reads oddly when announced).
   final String? semanticLabel;
-
-  /// Screen-reader hint describing the button's effect. Optional.
   final String? semanticHint;
-
-  @override
-  State<ClideButton> createState() => _ClideButtonState();
-}
-
-class _ClideButtonState extends State<ClideButton> {
-  bool _hovered = false;
-  bool _pressed = false;
+  final String? tooltip;
 
   @override
   Widget build(BuildContext context) {
     final tokens = ClideTheme.of(context).surface;
-    final enabled = widget.onPressed != null;
-
-    Color bg;
-    Color fg;
-    switch (widget.variant) {
-      case ClideButtonVariant.normal:
-        bg = _pressed
-            ? tokens.buttonActiveBackground
-            : _hovered
-                ? tokens.buttonHoverBackground
-                : tokens.buttonBackground;
-        fg = tokens.buttonForeground;
-      case ClideButtonVariant.primary:
-        bg = _pressed
-            ? tokens.panelActiveBorder
-            : _hovered
-                ? tokens.buttonActiveBackground
-                : tokens.buttonActiveBackground;
-        fg = tokens.globalBackground;
-      case ClideButtonVariant.subtle:
-        bg = _hovered
-            ? tokens.listItemHoverBackground
-            : tokens.listItemBackground;
-        fg = tokens.listItemForeground;
-    }
+    final enabled = onPressed != null;
 
     return Semantics(
       button: true,
       enabled: enabled,
-      label: widget.semanticLabel ?? widget.label,
-      hint: widget.semanticHint,
-      onTap: enabled ? widget.onPressed : null,
+      label: semanticLabel ?? label,
+      hint: semanticHint,
+      onTap: enabled ? onPressed : null,
       excludeSemantics: true,
-      child: MouseRegion(
-        cursor:
-            enabled ? SystemMouseCursors.click : SystemMouseCursors.forbidden,
-        onEnter: (_) => setState(() => _hovered = true),
-        onExit: (_) => setState(() => _hovered = false),
-        child: GestureDetector(
-          onTapDown: (_) => setState(() => _pressed = true),
-          onTapCancel: () => setState(() => _pressed = false),
-          onTapUp: (_) {
-            setState(() => _pressed = false);
-            widget.onPressed?.call();
-          },
-          child: Container(
-            padding: widget.padding,
+      child: ClideTappable(
+        cursor: enabled ? SystemMouseCursors.click : SystemMouseCursors.forbidden,
+        tooltip: tooltip,
+        onTap: onPressed,
+        builder: (ctx, hovered, pressed) {
+          Color bg;
+          Color fg;
+          switch (variant) {
+            case ClideButtonVariant.normal:
+              bg = pressed
+                  ? tokens.buttonActiveBackground
+                  : hovered
+                      ? tokens.buttonHoverBackground
+                      : tokens.buttonBackground;
+              fg = tokens.buttonForeground;
+            case ClideButtonVariant.primary:
+              bg = pressed ? tokens.panelActiveBorder : tokens.buttonActiveBackground;
+              fg = tokens.globalBackground;
+            case ClideButtonVariant.subtle:
+              bg = hovered ? tokens.listItemHoverBackground : tokens.listItemBackground;
+              fg = tokens.listItemForeground;
+          }
+
+          return Container(
+            padding: padding,
             decoration: BoxDecoration(
               color: bg,
               border: Border.all(color: tokens.buttonBorder, width: 1),
               borderRadius: BorderRadius.circular(3),
             ),
             child: ClideText(
-              widget.label,
+              label,
               color: fg,
-              fontWeight: widget.variant == ClideButtonVariant.primary
-                  ? FontWeight.w600
-                  : FontWeight.w500,
+              fontWeight: variant == ClideButtonVariant.primary ? FontWeight.w600 : FontWeight.w500,
             ),
-          ),
-        ),
+          );
+        },
       ),
     );
   }