fix: prepare stage one integration

frontend/src/App.vue

@@ -4,7 +4,7 @@ import { Activity, BookOpen, Bot, CheckCircle2, ChevronRight, Database, FileText
 import { askQuestion, createKnowledge, getHealth, getKnowledge } from './api'
 type Page='chat'|'knowledge'|'sources'|'evaluation'
 const page=ref<Page>('chat'), apiStatus=ref('检测中'), question=ref(''), busy=ref(false), search=ref(''), showForm=ref(false), error=ref(''), notice=ref('')
-const messages=ref([{role:'assistant',content:'你好！我是边疆红驿文旅问答原型。当前后端仅为基础接口，尚未接入知识检索和大语言模型。'}] as {role:string;content:string;sources?:{title:string;source_url?:string}[]}[])
+const messages=ref([{role:'assistant',content:'你好！我是边疆红驿文旅问答原型。当前后端仅为基础接口，尚未接入知识检索和大语言模型。'}] as {role:string;content:string;sources?:{title:string;source_url?:string|null}[]}[])
 const items=ref<any[]>([]), form=ref({title:'',category:'旅游资源',content:'',source_url:''})
 const nav=[{id:'chat',label:'智能问答',icon:MessageSquareText},{id:'knowledge',label:'知识库管理',icon:Database},{id:'sources',label:'来源与更新',icon:Globe2},{id:'evaluation',label:'实验评估',icon:Activity}] as const
 const filtered=computed(()=>items.value.filter(x=>`${x.title} ${x.category} ${x.content}`.toLowerCase().includes(search.value.toLowerCase())))
@@ -14,7 +14,7 @@ async function send(){const q=question.value.trim();if(!q||busy.value)return;mes
 async function save(){error.value='';notice.value='';try{await createKnowledge({...form.value,...(form.value.source_url?{source_url:form.value.source_url}:{})});form.value={title:'',category:'旅游资源',content:'',source_url:''};showForm.value=false;notice.value='已保存为待审核条目，尚未进入检索索引。';await refresh()}catch(e){error.value=e instanceof Error?e.message:'保存失败'}}
 </script>
 <template><div class="shell"><aside class="sidebar"><div class="brand"><div class="mark"><Bot :size="23"/></div><div><b>边疆红驿</b><small>NALATI KNOWLEDGE HUB</small></div></div><p class="muted label">工作空间</p><nav><button v-for="n in nav" :key="n.id" :class="{active:page===n.id}" @click="page=n.id"><component :is="n.icon" :size="18"/>{{n.label}}<ChevronRight v-if="page===n.id" class="chev" :size="15"/></button></nav><div class="side-bottom"><div class="tip"><ShieldCheck :size="17"/><div><b>可信知识服务</b><p>优先展示可核验来源，信息不足时明确提示。</p></div></div><p class="api">● API {{apiStatus}} <span>v0.1.0</span></p></div></aside><main><header><span>边疆红驿　/　{{nav.find(n=>n.id===page)?.label}}</span><div><span class="pill">● 原型阶段</span><i>研</i></div></header><section class="content">
-<div v-if="page==='chat'"><div class="heading"><div><small class="eyebrow"><Sparkles :size="14"/> LOCAL KNOWLEDGE ASSISTANT</small><h1>文旅知识，问得明白</h1><p>面向那拉提文旅与民宿服务的知识问答原型</p></div><span class="chip"><ShieldCheck :size="15"/> 来源可追溯 · 设计目标</span></div><div class="chat-layout"><div class="card chat"><div class="chat-head"><div class="mark"><Bot :size="20"/></div><div><b>边疆红驿助手</b><small>问答服务原型</small></div></div><div class="messages"><div v-for="(m,i) in messages" :key="i" class="message" :class="m.role"><small>{{m.role==='assistant'?'智能助手':'你'}}</small><p>{{m.content}}</p><div v-if="m.sources?.length" class="sources"><b><Link2 :size="14"/> 参考来源</b><a v-for="s in m.sources" :key="s.title" :href="s.source_url" target="_blank">{{s.title}}</a></div></div><p v-if="busy">正在请求后端…</p></div><form class="composer" @submit.prevent="send"><textarea v-model="question" placeholder="输入你想了解的文旅问题…" rows="2" @keydown.enter.exact.prevent="send"/><div><small>当前为基础接口，尚未接入真实检索</small><button class="primary" :disabled="busy||!question.trim()"><Send :size="15"/> 发送</button></div></form></div><aside class="suggest"><b><Sparkles :size="16"/> 你可以这样问</b><button @click="question='那拉提有哪些值得了解的旅游资源？'"><Globe2/>旅游资源 <ChevronRight/></button><button @click="question='有哪些经过核验的红色文化资料？'"><BookOpen/>红色文化 <ChevronRight/></button><button @click="question='民宿服务信息应如何核验？'"><ShieldCheck/>民宿服务 <ChevronRight/></button><div class="notice"><b><AlertCircle :size="15"/> 信息说明</b><p>本项目仍处于原型阶段。演示内容不代表已核验的地方文旅事实。</p></div></aside></div></div>
+<div v-if="page==='chat'"><div class="heading"><div><small class="eyebrow"><Sparkles :size="14"/> LOCAL KNOWLEDGE ASSISTANT</small><h1>文旅知识，问得明白</h1><p>面向那拉提文旅与民宿服务的知识问答原型</p></div><span class="chip"><ShieldCheck :size="15"/> 来源可追溯 · 设计目标</span></div><div class="chat-layout"><div class="card chat"><div class="chat-head"><div class="mark"><Bot :size="20"/></div><div><b>边疆红驿助手</b><small>问答服务原型</small></div></div><div class="messages"><div v-for="(m,i) in messages" :key="i" class="message" :class="m.role"><small>{{m.role==='assistant'?'智能助手':'你'}}</small><p>{{m.content}}</p><div v-if="m.sources?.length" class="sources"><b><Link2 :size="14"/> 参考来源</b><a v-for="s in m.sources" :key="s.title" :href="s.source_url ?? undefined" target="_blank">{{s.title}}</a></div></div><p v-if="busy">正在请求后端…</p></div><form class="composer" @submit.prevent="send"><textarea v-model="question" placeholder="输入你想了解的文旅问题…" rows="2" @keydown.enter.exact.prevent="send"/><div><small>当前为基础接口，尚未接入真实检索</small><button class="primary" :disabled="busy||!question.trim()"><Send :size="15"/> 发送</button></div></form></div><aside class="suggest"><b><Sparkles :size="16"/> 你可以这样问</b><button @click="question='那拉提有哪些值得了解的旅游资源？'"><Globe2/>旅游资源 <ChevronRight/></button><button @click="question='有哪些经过核验的红色文化资料？'"><BookOpen/>红色文化 <ChevronRight/></button><button @click="question='民宿服务信息应如何核验？'"><ShieldCheck/>民宿服务 <ChevronRight/></button><div class="notice"><b><AlertCircle :size="15"/> 信息说明</b><p>本项目仍处于原型阶段。演示内容不代表已核验的地方文旅事实。</p></div></aside></div></div>
 <div v-else-if="page==='knowledge'"><div class="heading"><div><small class="eyebrow"><Database :size="14"/> KNOWLEDGE MANAGEMENT</small><h1>知识库管理</h1><p>集中管理领域知识、来源和审核状态。</p></div><button class="primary" @click="showForm=!showForm"><Plus :size="16"/> 新增知识</button></div><div v-if="showForm" class="card form-card"><b>新增知识条目</b><form class="knowledge-form" @submit.prevent="save"><label>标题<input v-model="form.title" required maxlength="250"/></label><label>分类<select v-model="form.category"><option>红色文化</option><option>旅游资源</option><option>民宿服务</option><option>交通出行</option><option>其他</option></select></label><label class="wide">正文<textarea v-model="form.content" required rows="3"/></label><label class="wide">来源网址（可选）<input v-model="form.source_url" type="url" placeholder="https://..."/></label><div class="wide actions"><button type="button" class="secondary" @click="showForm=false">取消</button><button class="primary">保存条目</button></div></form></div><div class="stats"><div class="card stat"><small>知识条目</small><strong>{{items.length}}</strong><span>来自当前数据库</span></div><div class="card stat"><small>已核验</small><strong>{{items.filter(x=>x.verification_status==='verified').length}}</strong><span>需经过真实审核</span></div><div class="card stat"><small>待审核</small><strong>{{items.filter(x=>x.verification_status==='pending').length}}</strong><span>尚未进入检索索引</span></div></div><p v-if="notice" class="success">{{notice}}</p><p v-if="error" class="error">{{error}}</p><div class="card table-card"><div class="table-head"><div><b>知识条目</b><p>列表来自后端接口，不含预设真实资料。</p></div><label class="search"><Search :size="15"/><input v-model="search" placeholder="搜索知识"/></label></div><div class="scroll"><table><thead><tr><th>标题</th><th>分类</th><th>来源</th><th>状态</th><th>创建时间</th></tr></thead><tbody><tr v-for="x in filtered" :key="x.id"><td><b>{{x.title}}</b><small>{{x.content.slice(0,45)}}</small></td><td>{{x.category}}</td><td><a v-if="x.source_url" :href="x.source_url" target="_blank">打开来源</a><span v-else>未填写</span></td><td><em>{{x.verification_status==='pending'?'待审核':x.verification_status}}</em></td><td>{{new Date(x.created_at).toLocaleDateString()}}</td></tr><tr v-if="!filtered.length"><td colspan="5" class="empty">暂无条目，点击“新增知识”添加。</td></tr></tbody></table></div></div></div>
 <div v-else-if="page==='sources'"><div class="heading"><div><small class="eyebrow"><Globe2 :size="14"/> SOURCE OPERATIONS</small><h1>来源与更新</h1><p>为后续网页采集、审核、向量生成和版本切换预留界面。</p></div><span class="pill">● 功能规划中</span></div><div class="notice wide"><b><AlertCircle :size="16"/> 当前状态</b><p>此页面为静态原型。尚未连接网页抓取、定时任务或 Embedding 流程，不会自动更新知识。</p></div><div class="stats"><div class="card stat"><small>来源总数</small><strong>—</strong><span>待接入</span></div><div class="card stat"><small>待处理任务</small><strong>—</strong><span>后台队列尚未实现</span></div><div class="card stat"><small>最近更新</small><strong>—</strong><span>待接入更新记录</span></div></div><div class="card roadmap"><b>后续更新流程</b><div><span>01　获取来源</span><ChevronRight/><span>02　核验内容</span><ChevronRight/><span>03　生成向量</span><ChevronRight/><span>04　发布版本</span></div></div></div>
 <div v-else><div class="heading"><div><small class="eyebrow"><Activity :size="14"/> EVALUATION WORKSPACE</small><h1>实验评估</h1><p>展示实验方案与指标规划；当前不显示虚构实验结果。</p></div><span class="pill">● 尚未开展实验</span></div><div class="notice wide"><b><ShieldCheck :size="16"/> 实验原则</b><p>所有指标应来自真实测试问题、运行日志和明确的人工评分规则。下方仅列评价维度，不包含实验数值。</p></div><div class="stats"><div class="card stat"><small>回答正确性</small><strong class="pending">待测试</strong><span>依据人工评分规范</span></div><div class="card stat"><small>来源可追溯性</small><strong class="pending">待测试</strong><span>核对来源是否支持答案</span></div><div class="card stat"><small>响应时间与成本</small><strong class="pending">待测试</strong><span>记录耗时与实际费用</span></div></div><div class="card roadmap"><b>计划中的对照方案</b><div class="methods"><p><b>A　基础大语言模型</b><span>不提供项目知识库检索结果</span></p><p><b>B　关键词检索 RAG</b><span>关键词检索后生成答案</span></p><p><b>C　混合检索 RAG</b><span>融合关键词与向量语义检索</span></p></div></div></div><footer>边疆红驿 · 那拉提文旅智能问答 <span>工程原型 v0.1.0 · 尚非完整系统</span></footer></section></main></div></template>