fix: remove clipboard paste menu item, fix timeline line overlap, dim input placeholder

- Remove redundant "从剪贴板粘贴" option from attachment menu (long-press to paste natively)
- Remove super_clipboard dependency (no longer needed)
- Fix timeline vertical line overlapping icon nodes by using dynamic dotRadius
- Dim input field placeholder color to AppColors.textMuted

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

it0_app/lib/features/chat/presentation/pages/chat_page.dart

@@ -1,10 +1,8 @@
-import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:image_picker/image_picker.dart';
-import 'package:super_clipboard/super_clipboard.dart';
 import 'package:file_picker/file_picker.dart';
 import '../../../../core/theme/app_colors.dart';
 import '../../domain/entities/chat_message.dart';
@@ -93,11 +91,6 @@ class _ChatPageState extends ConsumerState<ChatPage> {
               title: const Text('拍照'),
               onTap: () { Navigator.pop(ctx); _pickImage(ImageSource.camera); },
             ),
-            ListTile(
-              leading: const Icon(Icons.content_paste),
-              title: const Text('从剪贴板粘贴'),
-              onTap: () { Navigator.pop(ctx); _pasteFromClipboard(); },
-            ),
             ListTile(
               leading: const Icon(Icons.attach_file),
               title: const Text('选择文件'),
@@ -193,58 +186,6 @@ class _ChatPageState extends ConsumerState<ChatPage> {
     }
   }
 
-  Future<void> _pasteFromClipboard() async {
-    final clipboard = SystemClipboard.instance;
-    if (clipboard == null) {
-      if (mounted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(content: Text('当前设备不支持剪贴板读取')),
-        );
-      }
-      return;
-    }
-
-    try {
-      final reader = await clipboard.read();
-      for (final item in reader.items) {
-        // Try PNG first, then JPEG
-        for (final format in [Formats.png, Formats.jpeg]) {
-          if (item.canProvide(format)) {
-            final completer = Completer<List<int>>();
-            item.getFile(format, (file) async {
-              try {
-                final bytes = await file.readAll();
-                completer.complete(bytes);
-              } catch (e) {
-                completer.completeError(e);
-              }
-            }, onError: (e) {
-              if (!completer.isCompleted) completer.completeError(e);
-            });
-            final bytes = await completer.future;
-            final mediaType = format == Formats.png ? 'image/png' : 'image/jpeg';
-            setState(() {
-              _pendingAttachments.add(ChatAttachment(
-                base64Data: base64Encode(bytes),
-                mediaType: mediaType,
-                fileName: 'clipboard.${format == Formats.png ? "png" : "jpg"}',
-              ));
-            });
-            return;
-          }
-        }
-      }
-    } catch (e) {
-      // Clipboard read failed
-    }
-
-    if (mounted) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('剪贴板中没有图片')),
-      );
-    }
-  }
-
   Future<void> _pickFile() async {
     final remaining = _maxAttachments - _pendingAttachments.length;
     if (remaining <= 0) {
@@ -673,6 +614,7 @@ class _ChatPageState extends ConsumerState<ChatPage> {
                   controller: _messageController,
                   decoration: InputDecoration(
                     hintText: isStreaming ? '追加指令...' : '输入指令...',
+                    hintStyle: TextStyle(color: AppColors.textMuted),
                     border: const OutlineInputBorder(
                       borderRadius: BorderRadius.all(Radius.circular(24)),
                     ),

it0_app/lib/features/chat/presentation/widgets/timeline_event_node.dart

@@ -40,12 +40,16 @@ class TimelineEventNode extends StatelessWidget {
   Widget build(BuildContext context) {
     // Use CustomPaint for the timeline line to avoid IntrinsicHeight which
     // causes bottom-overflow on long content.
+    // Icon nodes are 16px tall, plain dots are 10px. The gap in the
+    // vertical line must be large enough to avoid overlapping either.
+    final dotRadius = icon != null ? 10.0 : 6.0;
     return CustomPaint(
       painter: _TimelineLinePainter(
         color: AppColors.surfaceLight,
         isFirst: isFirst,
         isLast: isLast,
-        dotOffset: 14, // vertical center of the dot area
+        dotCenter: 14, // vertical center of the dot area
+        dotRadius: dotRadius,
         lineX: 14, // horizontal center of the 28px left column
       ),
       child: Row(
@@ -109,14 +113,16 @@ class _TimelineLinePainter extends CustomPainter {
   final Color color;
   final bool isFirst;
   final bool isLast;
-  final double dotOffset;
+  final double dotCenter;
+  final double dotRadius;
   final double lineX;
 
   _TimelineLinePainter({
     required this.color,
     required this.isFirst,
     required this.isLast,
-    required this.dotOffset,
+    required this.dotCenter,
+    required this.dotRadius,
     required this.lineX,
   });
 
@@ -126,15 +132,15 @@ class _TimelineLinePainter extends CustomPainter {
       ..color = color
       ..strokeWidth = 1.5;
 
-    // Line above the dot
+    // Line above the dot/icon
     if (!isFirst) {
-      canvas.drawLine(Offset(lineX, 0), Offset(lineX, dotOffset), paint);
+      canvas.drawLine(Offset(lineX, 0), Offset(lineX, dotCenter - dotRadius), paint);
     }
 
-    // Line below the dot
+    // Line below the dot/icon
     if (!isLast) {
       canvas.drawLine(
-        Offset(lineX, dotOffset + 10),
+        Offset(lineX, dotCenter + dotRadius),
         Offset(lineX, size.height),
         paint,
       );
@@ -145,7 +151,8 @@ class _TimelineLinePainter extends CustomPainter {
   bool shouldRepaint(_TimelineLinePainter oldDelegate) =>
       color != oldDelegate.color ||
       isFirst != oldDelegate.isFirst ||
-      isLast != oldDelegate.isLast;
+      isLast != oldDelegate.isLast ||
+      dotRadius != oldDelegate.dotRadius;
 }
 
 /// Static colored dot with optional icon for completed/error/idle states.

it0_app/pubspec.yaml

@@ -37,7 +37,6 @@ dependencies:
   gpt_markdown: ^1.1.5
   flutter_svg: ^2.0.10+1
   image_picker: ^1.1.2
-  super_clipboard: ^0.8.1
   file_picker: ^8.0.0
 
   # Voice