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_tappable.dart

@@ -1,16 +1,23 @@
+import 'package:clide/widgets/src/clide_tooltip.dart';
 import 'package:flutter/widgets.dart';
 
 class ClideTappable extends StatefulWidget {
   const ClideTappable({
     super.key,
-    required this.onTap,
     required this.builder,
+    this.onTap,
+    this.onLongPress,
+    this.onPressChanged,
     this.cursor = SystemMouseCursors.click,
+    this.tooltip,
   });
 
-  final VoidCallback onTap;
-  final Widget Function(BuildContext context, bool hovered) builder;
+  final Widget Function(BuildContext context, bool hovered, bool pressed) builder;
+  final VoidCallback? onTap;
+  final VoidCallback? onLongPress;
+  final ValueChanged<bool>? onPressChanged;
   final MouseCursor cursor;
+  final String? tooltip;
 
   @override
   State<ClideTappable> createState() => _ClideTappableState();
@@ -18,18 +25,36 @@ class ClideTappable extends StatefulWidget {
 
 class _ClideTappableState extends State<ClideTappable> {
   bool _hover = false;
+  bool _pressed = false;
+
+  void _setPressed(bool v) {
+    if (_pressed == v) return;
+    setState(() => _pressed = v);
+    widget.onPressChanged?.call(v);
+  }
 
   @override
   Widget build(BuildContext context) {
-    return MouseRegion(
+    Widget child = MouseRegion(
       cursor: widget.cursor,
       onEnter: (_) => setState(() => _hover = true),
-      onExit: (_) => setState(() => _hover = false),
+      onExit: (_) {
+        setState(() => _hover = false);
+        _setPressed(false);
+      },
       child: GestureDetector(
         behavior: HitTestBehavior.opaque,
         onTap: widget.onTap,
-        child: widget.builder(context, _hover),
+        onLongPress: widget.onLongPress,
+        onTapDown: (_) => _setPressed(true),
+        onTapUp: (_) => _setPressed(false),
+        onTapCancel: () => _setPressed(false),
+        child: widget.builder(context, _hover, _pressed),
       ),
     );
+    if (widget.tooltip != null) {
+      child = ClideTooltip(message: widget.tooltip!, child: child);
+    }
+    return child;
   }
 }