feat(mindspace): 悬浮聊天勾选资料联动、UI 与交互优化

勾选单个文件时 Agent 获知上下文并主动问候；打开悬浮窗使用新会话。
统一弹窗浅色主题、固定高度与输入区布局，支持点击外部收起。

Co-authored-by: Cursor <cursoragent@cursor.com>

src/components/SpaceChatPanel.tsx

@@ -1,8 +1,8 @@
-import { useEffect } from 'react';
+import { useEffect, useMemo } from 'react';
 import { useChat } from '../context/ChatProvider';
 import { INSUFFICIENT_BALANCE_NOTICE } from '../hooks/useTKMindChat';
 import type { PageEditSubChatBridge } from '../hooks/usePageEditSubChat';
-import type { MindSpaceChatContext, MindSpaceSaveCategory, PortalUser } from '../types';
+import type { MindSpaceChatContext, MindSpaceSaveCategory, PortalUser, Message } from '../types';
 import { formatContextChip } from '../utils/mindspaceChatContext';
 import { ChatPanel } from './ChatPanel';
 import { TKMindAvatar } from './TKMindAvatar';
@@ -17,6 +17,7 @@ export function SpaceChatPanel({
   chatBridge,
   hideOpenFullChat = false,
   title = 'TKMind',
+  prefillMessages = [],
 }: {
   open: boolean;
   context: MindSpaceChatContext;
@@ -31,6 +32,7 @@ export function SpaceChatPanel({
   chatBridge?: PageEditSubChatBridge;
   hideOpenFullChat?: boolean;
   title?: string;
+  prefillMessages?: Message[];
 }) {
   const mainChat = useChat();
   const chat = chatBridge ?? mainChat;
@@ -59,6 +61,15 @@ export function SpaceChatPanel({
     return () => window.removeEventListener('keydown', handleKeyDown);
   }, [open, onClose]);
 
+  const displayMessages = useMemo(() => {
+    if (!prefillMessages.length) return messages;
+    if (messages.some((message) => message.role === 'user')) return messages;
+    const extras = prefillMessages.filter(
+      (item) => !messages.some((message) => message.id && message.id === item.id),
+    );
+    return extras.length ? [...messages, ...extras] : messages;
+  }, [messages, prefillMessages]);
+
   if (!open) return null;
 
   const contextLabel = formatContextChip(context);
@@ -119,7 +130,7 @@ export function SpaceChatPanel({
       <ChatPanel
         variant="compact"
         user={user}
-        messages={messages}
+        messages={displayMessages}
         chatState={chatState}
         pendingTool={pendingTool}
         session={session}
@@ -132,7 +143,6 @@ export function SpaceChatPanel({
         onStop={stop}
         onApproveTool={approveTool}
         onPageSaved={onPageSaved}
-        onClose={onClose}
       />
     </div>
   );