feat(vscode-ide-companion): 增加代码编辑功能和文件操作支持

- 实现了与 Claude Code 类似的代码编辑功能
- 添加了文件打开、保存等操作的支持
- 优化了消息显示，增加了代码高亮和文件路径点击功能
- 改进了用户界面，增加了编辑模式切换和思考模式功能

packages/vscode-ide-companion/src/webview/components/toolcalls/shared/DiffDisplay.tsx

@@ -0,0 +1,72 @@
+/**
+ * @license
+ * Copyright 2025 Qwen Team
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Diff display component for showing file changes
+ */
+
+import type React from 'react';
+
+/**
+ * Props for DiffDisplay
+ */
+interface DiffDisplayProps {
+  path?: string;
+  oldText?: string | null;
+  newText?: string;
+  onOpenDiff?: () => void;
+}
+
+/**
+ * Display diff with before/after sections and option to open in VSCode diff viewer
+ */
+export const DiffDisplay: React.FC<DiffDisplayProps> = ({
+  path,
+  oldText,
+  newText,
+  onOpenDiff,
+}) => (
+  <div className="diff-display-container">
+    <div className="diff-header">
+      <div className="diff-file-path">
+        <strong>{path || 'Unknown file'}</strong>
+      </div>
+      {onOpenDiff && (
+        <button
+          className="open-diff-button"
+          onClick={onOpenDiff}
+          title="Open in VS Code diff viewer"
+        >
+          <svg width="16" height="16" viewBox="0 0 16 16" fill="none">
+            <path
+              d="M8 15A7 7 0 1 1 8 1a7 7 0 0 1 0 14zm0 1A8 8 0 1 0 8 0a8 8 0 0 0 0 16z"
+              fill="currentColor"
+            />
+            <path
+              d="M5.25 8a.75.75 0 0 1 .75-.75h4a.75.75 0 0 1 0 1.5H6a.75.75 0 0 1-.75-.75z"
+              fill="currentColor"
+            />
+          </svg>
+          Open Diff
+        </button>
+      )}
+    </div>
+    {oldText !== undefined && (
+      <div className="diff-section">
+        <div className="diff-label">Before:</div>
+        <pre className="code-block">
+          <div className="code-content">{oldText || '(empty)'}</div>
+        </pre>
+      </div>
+    )}
+    {newText !== undefined && (
+      <div className="diff-section">
+        <div className="diff-label">After:</div>
+        <pre className="code-block">
+          <div className="code-content">{newText}</div>
+        </pre>
+      </div>
+    )}
+  </div>
+);