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>

mindspace-chat-context.test.mjs

@@ -3,6 +3,7 @@ import test from 'node:test';
 import {
   buildContextPrefix,
   buildMindSpaceChatContext,
+  buildSelectedAssetGreeting,
   formatContextChip,
   mindspaceChatContextInternals,
 } from './mindspace-chat-context.mjs';
@@ -169,3 +170,103 @@ test('excerptContent strips html and truncates long text', () => {
     `${'a'.repeat(9)}…`,
   );
 });
+
+test('buildMindSpaceChatContext exposes single selected asset as focused asset', () => {
+  const asset = {
+    id: 'asset-9',
+    displayName: 'Q1-report.pdf',
+    mimeType: 'application/pdf',
+    filename: 'Q1-report.pdf',
+    sizeBytes: 1200,
+    categoryCode: 'oa',
+    assetType: 'file',
+  };
+  const context = buildMindSpaceChatContext({
+    space: sampleSpace,
+    selectedCategory: sampleCategory,
+    selectedPageId: null,
+    pages: [],
+    assets: [asset],
+    selectedAssets: [asset],
+    route: '/space?category=oa',
+  });
+
+  assert.equal(context.selectedAssets?.length, 1);
+  assert.equal(context.focusedAsset?.id, 'asset-9');
+  assert.equal(formatContextChip(context), '已选 · Q1-report.pdf');
+});
+
+test('buildContextPrefix binds deictic references to a single checked asset', () => {
+  const asset = {
+    id: 'asset-9',
+    displayName: 'sales.xlsx',
+    mimeType: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+    filename: 'sales.xlsx',
+    categoryCode: 'oa',
+  };
+  const prefix = buildContextPrefix(
+    buildMindSpaceChatContext({
+      space: sampleSpace,
+      selectedCategory: sampleCategory,
+      selectedPageId: null,
+      pages: [],
+      assets: [asset],
+      selectedAssets: [asset],
+      route: '/space?category=oa',
+      h5ApiBase: 'http://127.0.0.1:8081',
+    }),
+  );
+
+  assert.match(prefix, /【界面勾选资料（硬性）】/);
+  assert.match(prefix, /sales\.xlsx（id: asset-9/);
+  assert.match(prefix, /DELETE \/api\/mindspace\/v1\/assets\/asset-9/);
+  assert.match(prefix, /指代「这个文件」「这份报告」「这个数据」时\*\*必须\*\*指该勾选资料/);
+});
+
+test('buildContextPrefix requires clarification when multiple assets are checked', () => {
+  const assets = [
+    { id: 'asset-a', displayName: 'a.pdf', mimeType: 'application/pdf' },
+    { id: 'asset-b', displayName: 'b.csv', mimeType: 'text/csv' },
+  ];
+  const prefix = buildContextPrefix(
+    buildMindSpaceChatContext({
+      space: sampleSpace,
+      selectedCategory: sampleCategory,
+      selectedPageId: null,
+      pages: [],
+      assets,
+      selectedAssets: assets,
+      route: '/space?category=oa',
+    }),
+  );
+
+  assert.match(prefix, /同时勾选了 2 份资料/);
+  assert.match(prefix, /必须先追问/);
+  assert.doesNotMatch(prefix, /当前聚焦资料/);
+  assert.equal(formatContextChip(buildMindSpaceChatContext({
+    space: sampleSpace,
+    selectedCategory: sampleCategory,
+    selectedPageId: null,
+    pages: [],
+    assets,
+    selectedAssets: assets,
+    route: '/space?category=oa',
+  })), '已选 2 项资料');
+});
+
+test('buildSelectedAssetGreeting adapts wording to asset kind', () => {
+  assert.match(
+    buildSelectedAssetGreeting({
+      displayName: 'sales.xlsx',
+      mimeType: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
+    }),
+    /这份数据表/,
+  );
+  assert.match(
+    buildSelectedAssetGreeting({
+      displayName: 'review.pdf',
+      mimeType: 'application/pdf',
+    }),
+    /这份报告/,
+  );
+});