feat(server): KB prompt优化、字幕修复、S2S重连、助手配置API

- assistantProfileConfig: KB answer prompt改为分层策略(严格产品信息+灵活常识补充)
- nativeVoiceGateway: S2S upstream自动重连(最多50次)、event 351字幕debounce(800ms取最长文本)
- toolExecutor: 确定性query改写增强、KB查询传递session上下文
- contextKeywordTracker: 支持KB话题记忆优先enrichment
- contentSafeGuard: 新增品牌安全内容过滤服务
- assistantProfileService: 新增助手配置CRUD服务
- routes/assistantProfile: 新增助手配置API路由
- knowledgeKeywords: 扩展KB关键词词典
- fastAsrCorrector: ASR纠错规则更新
- tests/: KB prompt测试、保护窗口测试、Viking性能测试
- docs/: 助手配置API文档、系统提示词目录

test2/server/tests/_test_single.js

@@ -0,0 +1,70 @@
+const path = require('path');
+const https = require('https');
+const fs = require('fs');
+
+// 加载 .env
+const envPath = path.join(__dirname, '../.env');
+if (fs.existsSync(envPath)) {
+  fs.readFileSync(envPath, 'utf8').split('\n').forEach(line => {
+    const t = line.trim();
+    if (!t || t.startsWith('#')) return;
+    const i = t.indexOf('=');
+    if (i > 0) {
+      const k = t.slice(0, i).trim();
+      let v = t.slice(i + 1).trim();
+      if ((v.startsWith('"') && v.endsWith('"')) || (v.startsWith("'") && v.endsWith("'")))
+        v = v.slice(1, -1);
+      if (!process.env[k]) process.env[k] = v;
+    }
+  });
+}
+
+const PROMPT = '你是大沃的智能助手，负责回答与PM-FitLine德国产品相关的问题。知识库涵盖近50款PM-FitLine产品的完整资料（成分、用法、剂量、价格、规格、搭配方案、好转反应等）及117个常见问答。回答规则：产品相关具体信息必须严格依据知识库，不得猜测或自行补充；公司背景、健康常识可适当补充。产品常有别名（小红=艾特维、大白=倍适、小白=维适多等），请注意识别。不得编造产品名或数据。PM是营养品非药物，涉及疾病建议咨询医生。若知识库无相关内容，坦诚说明并建议咨询推荐人。回答口语化、简洁，1-3句给结论，150字内。';
+
+const QUERY = process.argv[2] || '一成系统 赋能 德国PM';
+
+const m = process.env.VOLC_ARK_KB_MODEL || process.env.VOLC_ARK_KNOWLEDGE_ENDPOINT_ID;
+const ak = process.env.VOLC_ARK_API_KEY || process.env.VOLC_ACCESS_KEY_ID;
+const ids = (process.env.VOLC_ARK_KNOWLEDGE_BASE_IDS || '').split(',').map(s => s.trim()).filter(Boolean);
+const th = parseFloat(process.env.VOLC_ARK_KNOWLEDGE_THRESHOLD) || 0.3;
+
+const body = JSON.stringify({
+  model: m,
+  messages: [
+    { role: 'system', content: PROMPT },
+    { role: 'user', content: QUERY },
+  ],
+  metadata: { knowledge_base: { dataset_ids: ids, top_k: 3, threshold: th } },
+  stream: false,
+  max_tokens: 80,
+  thinking: { type: 'disabled' },
+});
+
+const t0 = Date.now();
+const req = https.request({
+  hostname: 'ark.cn-beijing.volces.com',
+  path: '/api/v3/chat/completions',
+  method: 'POST',
+  headers: {
+    'Content-Type': 'application/json',
+    'Authorization': `Bearer ${ak}`,
+    'Content-Length': Buffer.byteLength(body),
+  },
+  timeout: 15000,
+}, (res) => {
+  let chunks = [];
+  res.on('data', c => chunks.push(c));
+  res.on('end', () => {
+    const j = JSON.parse(Buffer.concat(chunks).toString());
+    const content = j.choices?.[0]?.message?.content || '(empty)';
+    const u = j.usage || {};
+    const ms = Date.now() - t0;
+    const isNoHit = /未找到|未提及|暂无|没有相关|无法|不确定/.test(content);
+    console.log(`\n检索词: "${QUERY}"`);
+    console.log(`延迟: ${ms}ms | tokens: ${u.prompt_tokens}->${u.completion_tokens} | ${isNoHit ? '❌NO-HIT' : '✅HIT'}`);
+    console.log(`\n回答:\n${content}\n`);
+  });
+});
+req.on('error', e => console.error('ERROR:', e.message));
+req.write(body);
+req.end();