feat(asl): Add DeepSearch smart literature retrieval MVP

Features:
- Integrate unifuncs DeepSearch API (OpenAI compatible protocol)
- SSE real-time streaming for AI thinking process display
- Natural language input, auto-generate PubMed search strategy
- Extract and display PubMed literature links
- Database storage for task records (asl_research_tasks)

Backend:
- researchService.ts - Core business logic with SSE streaming
- researchController.ts - SSE stream endpoint
- researchWorker.ts - Async task worker (backup mode)
- schema.prisma - AslResearchTask model

Frontend:
- ResearchSearch.tsx - Search page with unified content stream
- ResearchSearch.css - Styling (unifuncs-inspired simple design)
- ASLLayout.tsx - Enable menu item
- api/index.ts - Add research API functions

API Endpoints:
- POST /api/v1/asl/research/stream - SSE streaming search
- POST /api/v1/asl/research/tasks - Async task creation
- GET /api/v1/asl/research/tasks/:taskId/status - Task status

Documentation:
- Development record for DeepSearch integration
- Update ASL module status (v1.5)
- Update system status (v3.7)

Known limitations:
- SSE mode, task interrupts when leaving page
- Cost ~0.3 RMB per search (unifuncs API)

backend/scripts/test-unifuncs-deepsearch.ts

@@ -0,0 +1,120 @@
+/**
+ * unifuncs DeepSearch API 快速验证脚本
+ * 
+ * 运行方式：
+ * cd backend
+ * npx tsx scripts/test-unifuncs-deepsearch.ts
+ */
+
+import OpenAI from 'openai';
+
+// ========== 配置 ==========
+const UNIFUNCS_API_KEY = 'sk-2fNwqUH73elGq0aDKJEM4ReqP7Ry0iqHo4OXyidDe2WpQ9XQ';
+const UNIFUNCS_BASE_URL = 'https://api.unifuncs.com/deepsearch/v1';
+
+// ========== 测试用例 ==========
+const TEST_QUERIES = [
+  // 简单测试
+  '糖尿病 SGLT2抑制剂 心血管 RCT',
+  
+  // 复杂临床问题
+  // '乳腺癌免疫治疗最新系统综述，近3年的研究进展',
+];
+
+// ========== 主函数 ==========
+async function testDeepSearch() {
+  console.log('🚀 unifuncs DeepSearch API 验证测试\n');
+  console.log('=' .repeat(60));
+
+  const client = new OpenAI({
+    baseURL: UNIFUNCS_BASE_URL,
+    apiKey: UNIFUNCS_API_KEY,
+  });
+
+  for (const query of TEST_QUERIES) {
+    console.log(`\n📝 测试查询: "${query}"\n`);
+    console.log('-'.repeat(60));
+
+    try {
+      const startTime = Date.now();
+
+      // 方式1: 流式响应（推荐用于验证）
+      const stream = await client.chat.completions.create({
+        model: 's2',
+        messages: [{ role: 'user', content: query }],
+        stream: true,
+        // @ts-ignore - unifuncs 扩展参数
+        introduction: '你是一名专业的临床研究文献检索专家，请在 PubMed 中检索相关文献。输出每篇文献的 PMID、标题、作者、期刊、发表年份、研究类型。',
+        max_depth: 10,  // 验证时用较小的深度，加快速度
+        domain_scope: ['https://pubmed.ncbi.nlm.nih.gov/'],
+        domain_blacklist: ['wanfang.com', 'cnki.net'],
+        reference_style: 'link',
+      } as any);
+
+      let thinking = false;
+      let thinkingContent = '';
+      let responseContent = '';
+
+      console.log('📡 流式响应中...\n');
+
+      for await (const chunk of stream) {
+        const delta = chunk.choices[0]?.delta;
+        
+        // 处理思考过程 (reasoning_content)
+        if ((delta as any)?.reasoning_content) {
+          if (!thinking) {
+            console.log('💭 [思考过程]');
+            thinking = true;
+          }
+          const content = (delta as any).reasoning_content;
+          thinkingContent += content;
+          process.stdout.write(content);
+        } 
+        // 处理正式回答 (content)
+        else if (delta?.content) {
+          if (thinking) {
+            console.log('\n\n📄 [检索结果]');
+            thinking = false;
+          }
+          responseContent += delta.content;
+          process.stdout.write(delta.content);
+        }
+      }
+
+      const endTime = Date.now();
+      const duration = ((endTime - startTime) / 1000).toFixed(2);
+
+      console.log('\n\n' + '='.repeat(60));
+      console.log(`✅ 测试完成！耗时: ${duration} 秒`);
+      console.log(`📊 思考过程长度: ${thinkingContent.length} 字符`);
+      console.log(`📊 回答内容长度: ${responseContent.length} 字符`);
+
+      // 尝试提取 PMID
+      const pmidMatches = responseContent.match(/PMID[:\s]*(\d+)/gi) || [];
+      const pubmedLinks = responseContent.match(/pubmed\.ncbi\.nlm\.nih\.gov\/(\d+)/gi) || [];
+      const totalPmids = new Set([
+        ...pmidMatches.map(m => m.replace(/PMID[:\s]*/i, '')),
+        ...pubmedLinks.map(m => m.replace(/pubmed\.ncbi\.nlm\.nih\.gov\//i, '')),
+      ]);
+      
+      console.log(`📚 检索到的文献数量: ${totalPmids.size} 篇`);
+      if (totalPmids.size > 0) {
+        console.log(`📚 PMID 列表: ${[...totalPmids].slice(0, 10).join(', ')}${totalPmids.size > 10 ? '...' : ''}`);
+      }
+
+    } catch (error: any) {
+      console.error('\n❌ 测试失败:', error.message);
+      if (error.response) {
+        console.error('响应状态:', error.response.status);
+        console.error('响应数据:', error.response.data);
+      }
+    }
+  }
+
+  console.log('\n' + '='.repeat(60));
+  console.log('🏁 所有测试完成！');
+}
+
+// ========== 运行 ==========
+testDeepSearch().catch(console.error);
+