feat(ui): 演化历史条目增加可展开差异视图 + 文件变更标签

点击展开显示 soul/instructions/profile 变更内容，不再截断原因文本。

desktop/src/components/IdentityChangeProposal.tsx

@@ -275,30 +275,81 @@ function HistoryItem({
   onRestore: () => void;
   isRestoring: boolean;
 }) {
+  const [expanded, setExpanded] = useState(false);
   const timeAgo = getTimeAgo(snapshot.timestamp);
 
+  // Determine which files changed
+  const fileEntries: Array<{ key: string; label: string; color: string; content: string }> = [];
+  if (snapshot.files?.soul) {
+    fileEntries.push({ key: 'soul', label: 'Soul', color: 'text-purple-600 dark:text-purple-400', content: snapshot.files.soul });
+  }
+  if (snapshot.files?.instructions) {
+    fileEntries.push({ key: 'instructions', label: 'Instructions', color: 'text-blue-600 dark:text-blue-400', content: snapshot.files.instructions });
+  }
+  if (snapshot.files?.user_profile) {
+    fileEntries.push({ key: 'user_profile', label: 'Profile', color: 'text-emerald-600 dark:text-emerald-400', content: snapshot.files.user_profile });
+  }
+
   return (
-    <div className="flex items-start gap-3 p-3 rounded-lg bg-gray-50 dark:bg-gray-800/50 border border-gray-100 dark:border-gray-700">
+    <div className="rounded-lg bg-gray-50 dark:bg-gray-800/50 border border-gray-100 dark:border-gray-700">
-      <div className="w-8 h-8 rounded-lg bg-gray-200 dark:bg-gray-700 flex items-center justify-center flex-shrink-0">
+      <div
-        <History className="w-4 h-4 text-gray-500 dark:text-gray-400" />
+        className="flex items-start gap-3 p-3 cursor-pointer hover:bg-gray-100 dark:hover:bg-gray-800/70"
-      </div>
+        onClick={() => setExpanded(!expanded)}
-      <div className="flex-1 min-w-0">
+      >
-        <div className="flex items-center justify-between gap-2">
+        <div className="w-8 h-8 rounded-lg bg-gray-200 dark:bg-gray-700 flex items-center justify-center flex-shrink-0">
-          <span className="text-xs text-gray-500 dark:text-gray-400">{timeAgo}</span>
+          <History className="w-4 h-4 text-gray-500 dark:text-gray-400" />
-          <Button
+        </div>
-            variant="ghost"
+        <div className="flex-1 min-w-0">
-            size="sm"
+          <div className="flex items-center justify-between gap-2">
-            onClick={onRestore}
+            <span className="text-xs text-gray-500 dark:text-gray-400">{timeAgo}</span>
-            disabled={isRestoring}
+            <div className="flex items-center gap-2">
-            className="text-xs text-gray-500 hover:text-orange-600"
+              {fileEntries.length > 0 && (
-          >
+                <span className="text-xs text-gray-400">
-            恢复
+                  {fileEntries.length} 个文件
-          </Button>
+                </span>
+              )}
+              <Button
+                variant="ghost"
+                size="sm"
+                onClick={(e) => { e.stopPropagation(); onRestore(); }}
+                disabled={isRestoring}
+                className="text-xs text-gray-500 hover:text-orange-600"
+              >
+                恢复
+              </Button>
+            </div>
+          </div>
+          <p className="text-sm text-gray-700 dark:text-gray-300 mt-1">
+            {snapshot.reason || '自动快照'}
+          </p>
+          {fileEntries.length > 0 && (
+            <div className="flex gap-1 mt-1.5">
+              {fileEntries.map(({ key, label, color }) => (
+                <span
+                  key={key}
+                  className={`text-[10px] px-1.5 py-0.5 rounded bg-gray-200 dark:bg-gray-700 ${color}`}
+                >
+                  {label}
+                </span>
+              ))}
+            </div>
+          )}
         </div>
-        <p className="text-sm text-gray-700 dark:text-gray-300 mt-1 truncate">
-          {snapshot.reason || '自动快照'}
-        </p>
       </div>
+
+      {expanded && fileEntries.length > 0 && (
+        <div className="px-3 pb-3 pt-1 border-t border-gray-200 dark:border-gray-700 space-y-2">
+          {fileEntries.map(({ key, label, color, content }) => (
+            <div key={key}>
+              <div className={`text-xs font-medium ${color} mb-1`}>{label}</div>
+              <pre className="text-xs text-gray-600 dark:text-gray-400 whitespace-pre-wrap max-h-32 overflow-y-auto bg-white dark:bg-gray-900 p-2 rounded">
+                {content.slice(0, 500)}
+                {content.length > 500 ? '...' : ''}
+              </pre>
+            </div>
+          ))}
+        </div>
+      )}
     </div>
   );
 }