refactor: action buttons and scroll to bottom ui/ux

lib/shared/widgets/chat_action_button.dart

@@ -0,0 +1,103 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:conduit/shared/theme/theme_extensions.dart';
+import 'package:conduit/core/services/platform_service.dart';
+import 'package:conduit/core/services/settings_service.dart';
+
+class ChatActionButton extends ConsumerStatefulWidget {
+  final IconData icon;
+  final String label;
+  final VoidCallback? onTap;
+  final EdgeInsetsGeometry padding;
+  final BorderRadius? borderRadius;
+
+  const ChatActionButton({
+    super.key,
+    required this.icon,
+    required this.label,
+    this.onTap,
+    this.padding = const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+    this.borderRadius,
+  });
+
+  @override
+  ConsumerState<ChatActionButton> createState() => _ChatActionButtonState();
+}
+
+class _ChatActionButtonState extends ConsumerState<ChatActionButton> {
+  bool _pressed = false;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = context.conduitTheme;
+    final hapticEnabled = ref.read(hapticEnabledProvider);
+    final radius = widget.borderRadius ?? BorderRadius.circular(AppBorderRadius.lg);
+    final overlay = theme.buttonPrimary.withValues(alpha: 0.08);
+
+    return Tooltip(
+      message: widget.label,
+      waitDuration: const Duration(milliseconds: 600),
+      child: Semantics(
+        button: true,
+        label: widget.label,
+        child: AnimatedScale(
+          scale: _pressed ? 0.98 : 1.0,
+          duration: const Duration(milliseconds: 120),
+          curve: Curves.easeOutCubic,
+          child: Material(
+            color: Colors.transparent,
+            child: InkWell(
+              borderRadius: radius,
+              splashColor: overlay,
+              highlightColor: theme.textPrimary.withValues(alpha: 0.06),
+              onHighlightChanged: (v) => setState(() => _pressed = v),
+              onTap: widget.onTap == null
+                  ? null
+                  : () {
+                      PlatformService.hapticFeedbackWithSettings(
+                        type: HapticType.selection,
+                        hapticEnabled: hapticEnabled,
+                      );
+                      widget.onTap!();
+                    },
+              child: Ink(
+                decoration: BoxDecoration(
+                  color: theme.textPrimary.withValues(alpha: 0.04),
+                  borderRadius: radius,
+                  border: Border.all(
+                    color: theme.textPrimary.withValues(alpha: 0.08),
+                    width: BorderWidth.regular,
+                  ),
+                ),
+                child: Padding(
+                  padding: widget.padding,
+                  child: Row(
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      Icon(
+                        widget.icon,
+                        size: IconSize.sm,
+                        color: theme.textPrimary.withValues(alpha: 0.8),
+                      ),
+                      const SizedBox(width: Spacing.xs),
+                      Text(
+                        widget.label,
+                        style: TextStyle(
+                          fontSize: AppTypography.labelMedium,
+                          color: theme.textPrimary.withValues(alpha: 0.8),
+                          fontWeight: FontWeight.w500,
+                          letterSpacing: 0.2,
+                        ),
+                      ),
+                    ],
+                  ),
+                ),
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+

lib/shared/widgets/markdown/markdown_config.dart

@@ -43,7 +43,7 @@ class ConduitMarkdownConfig {
         LinkConfig(
           style: TextStyle(
             color: theme.buttonPrimary,
-            decoration: TextDecoration.underline,
+            decoration: TextDecoration.none,
           ),
           onTap: (url) async {
             if (await canLaunchUrlString(url)) {

lib/shared/widgets/measure_size.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+
+typedef OnWidgetSizeChange = void Function(Size size);
+
+class MeasureSize extends SingleChildRenderObjectWidget {
+  final OnWidgetSizeChange onChange;
+
+  const MeasureSize({super.key, required this.onChange, required Widget child})
+      : super(child: child);
+
+  @override
+  RenderObject createRenderObject(BuildContext context) {
+    return _MeasureSizeRenderObject(onChange);
+  }
+
+  @override
+  void updateRenderObject(
+      BuildContext context, covariant _MeasureSizeRenderObject renderObject) {
+    renderObject.onChange = onChange;
+  }
+}
+
+class _MeasureSizeRenderObject extends RenderProxyBox {
+  _MeasureSizeRenderObject(this.onChange);
+
+  OnWidgetSizeChange onChange;
+  Size? _oldSize;
+
+  @override
+  void performLayout() {
+    super.performLayout();
+    Size? newSize = child?.size;
+    if (_oldSize == newSize || newSize == null) return;
+    _oldSize = newSize;
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      onChange(newSize);
+    });
+  }
+}