feat: 数据源统一与前端预览修复

=== 后端核心 ===
- db_helper: 统一数据库访问抽象层
- system.py API:
  * 参数绑定修复: 使用 Body(embed=True) 接收 JSON
  * 添加请求日志记录
- sync.py: 仅导出 DB→JSON（备份）

=== 合规与流水线 ===
- compliance_checker: 标签检测优化（仅检查容器，避免正文误判）
- 所有脚本（creator/collector/writer/outline/research等）统一使用数据库

=== 前端改版 ===
- topics.html:
  * 创作/优化 API 路径修正
  * 预览弹窗重设计：多平台并行加载、富文本显示、单复制按钮
  * 状态中文映射（getStatusLabel）
  * 认证检查
- 所有 HTML 静态资源路径修复（移除 /static 前缀）

=== 数据一致性 ===
- 数据库状态统一为英文（pending/review/ready/published）
- 前端显示中文化映射

已测试 A03 流水线完整通过。

platform/frontend/topics.html

@@ -4,7 +4,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>宇之然内容创作平台 - 选题管理</title>
-    <link rel="stylesheet" href="/static/element-plus/index.css">
+    <link rel="stylesheet" href="element-plus.css">
     <style>
         * { margin: 0; padding: 0; box-sizing: border-box; }
         body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; background: #f5f7fa; }
@@ -97,7 +97,7 @@
                 <button class="sidebar-btn active">📋 选题管理</button>
                 <button class="sidebar-btn" @click="redirectToPage('logs.html')">📄 系统日志</button>
                 <button v-if="isAdmin" class="sidebar-btn" @click="redirectToPage('users.html')">👥 用户管理</button>
-                            <button v-if="isAdmin" class="sidebar-btn" @click="redirectToPage('admin.html')">⚙️ 系统管理</button>
+                            <button v-if="isAdmin" class="sidebar-btn" @click="redirectToPage('admin.html')">⚙️ 系统</button>
 </aside>
             <main class="content-area">
                 <div class="card">
@@ -124,7 +124,7 @@
                             <el-table-column prop="title" label="标题" min-width="200"></el-table-column>
                             <el-table-column prop="field" label="领域" width="100"></el-table-column>
                             <el-table-column prop="status" label="状态" width="90">
-                                <template #default="scope"><span class="status-badge"><span class="status-dot" :class="scope.row.status"></span>{{ scope.row.status }}</span></template>
+                                <template #default="scope"><span class="status-badge"><span class="status-dot" :class="scope.row.status"></span>{{ getStatusLabel(scope.row.status) }}</span></template>
                             </el-table-column>
                             <el-table-column prop="compliance_score" label="合规分" width="90">
                                 <template #default="scope"><el-progress :percentage="scope.row.compliance_score || 0" :format="() => scope.row.compliance_score || '-'" :stroke-width="15"></el-progress></template>
@@ -149,7 +149,7 @@
                             <div v-for="(topic, index) in filteredTopics" :key="topic.id" class="topic-card">
                                 <div class="topic-card-header">
                                     <div class="topic-card-title">{{ topic.id }}. {{ topic.title }}</div>
-                                    <el-tag :type="getStatusType(topic.status)" size="small">{{ topic.status }}</el-tag>
+                                    <el-tag :type="getStatusType(topic.status)" size="small">{{ getStatusLabel(topic.status) }}</el-tag>
                                 </div>
                                 <div class="topic-card-tags">
                                     <el-tag size="small" type="info">{{ topic.field }}</el-tag>
@@ -179,18 +179,30 @@
             <button class="mobile-nav-btn active">📋 选题</button>
             <button class="mobile-nav-btn" @click="redirectToPage('logs.html')">📄 日志</button>
             <button v-if="isAdmin" class="mobile-nav-btn" @click="redirectToPage('users.html')">👥 用户</button>
-                    <button v-if="isAdmin" class="mobile-nav-btn">⚙️ 系统管理</button>
+                    <button v-if="isAdmin" class="mobile-nav-btn" @click="redirectToPage('admin.html')">⚙️ 系统</button>
 </nav>
         <!-- 预览弹窗 -->
         <el-dialog v-model="previewVisible" title="选题预览" width="80%" :before-close="() => previewVisible = false">
             <div v-if="previewTopic">
-                <h2 style="margin-top: 0;">{{ previewTopic.title }}</h2>
-                <div class="preview-content" style="max-height: 60vh; overflow-y: auto; margin: 16px 0; padding: 16px; border: 1px solid #ebeef5; border-radius: 8px; background: #fafafa;">
-                    {{ previewTopic.content || '暂无内容' }}
+                <!-- 平台切换按钮 -->
+                <div style="margin-bottom: 16px; display: flex; justify-content: flex-end; gap: 8px;">
+                    <el-button-group>
+                        <el-button :type="previewPlatform === 'zhihu' ? 'primary' : 'default'" @click="previewPlatform = 'zhihu'">知乎</el-button>
+                        <el-button :type="previewPlatform === 'wechat' ? 'primary' : 'default'" @click="previewPlatform = 'wechat'">微信公众号</el-button>
+                        <el-button :type="previewPlatform === 'xiaohongshu' ? 'primary' : 'default'" @click="previewPlatform = 'xiaohongshu'">小红书</el-button>
+                    </el-button-group>
                 </div>
+
+                <h2 style="margin-top: 0;">{{ previewTopic.title }}</h2>
+                
+                <!-- 富文本内容预览（v-html 渲染） -->
+                <div class="preview-content" v-html="getPreviewHtml(previewPlatform)" 
+                     style="max-height: 60vh; overflow-y: auto; margin: 16px 0; padding: 16px; border: 1px solid #ebeef5; border-radius: 8px; background: #fafafa;">
+                </div>
+
                 <div class="preview-footer" style="font-size: 14px; color: #909399;">
                     <div>创建时间：{{ formatDate(previewTopic.created_at) }}</div>
-                    <div>状态：{{ previewTopic.status }}</div>
+                    <div>状态：{{ getStatusLabel(previewTopic.status) }}</div>
                     <div v-if="previewTopic.generated_at">创作时间：{{ formatDate(previewTopic.generated_at) }}</div>
                     <div v-if="previewTopic.published_at">发布时间：{{ formatDate(previewTopic.published_at) }}</div>
                 </div>
@@ -198,15 +210,13 @@
             <template #footer>
                 <div class="dialog-footer">
                     <el-button @click="previewVisible = false">关闭</el-button>
-                    <el-button type="primary" @click="copyContent('微信公众号')">复制并发布到微信公众号</el-button>
-                    <el-button type="primary" @click="copyContent('知乎')">复制并发布到知乎</el-button>
-                    <el-button type="primary" @click="copyContent('小红书')">复制并发布到小红书</el-button>
+                    <el-button type="primary" @click="copyContent(previewPlatform)">复制并发布到{{ platformName(previewPlatform) }}</el-button>
                 </div>
             </template>
         </el-dialog>
     </div>
-    <script src="/static/vue/vue.global.js"></script>
-    <script src="/static/element-plus/index.full.min.js"></script>
+    <script src="vue.global.prod.js"></script>
+    <script src="element-plus.full.js"></script>
     
 <script>
 const TopicsApp = {
@@ -222,7 +232,9 @@ const TopicsApp = {
             stats: { total: 0, pending: 0, review: 0, ready: 0, published: 0, today: 0 },
             topics: [],
             previewVisible: false,
-            previewTopic: null
+            previewTopic: null,
+            previewPlatform: 'zhihu',
+            platformContents: {}
         }
     },
     computed: {
@@ -285,18 +297,100 @@ const TopicsApp = {
         async triggerGenerateSelected() {
             if (!this.selectedTopicIds.length) return;
             this.$message.success('批量创作已启动');
-            this.selectedTopicIds = [];
-            await this.fetchTopics();
+            try {
+                const token = localStorage.getItem('authToken');
+                if (!token) {
+                    this.$message.error('请先登录');
+                    return;
+                }
+                // 取第一个选题（当前简单实现）
+                const topicId = this.selectedTopicIds[0];
+                const response = await fetch('/api/system/generate/run', {
+                    method: 'POST',
+                    headers: {
+                        'Authorization': 'Bearer ' + token,
+                        'Content-Type': 'application/json'
+                    },
+                    body: JSON.stringify({ topic_id: topicId })
+                });
+                if (!response.ok) {
+                    const errorData = await response.json().catch(() => ({}));
+                    throw new Error(errorData.detail || `请求失败: ${response.status}`);
+                }
+                await response.json();
+                this.$message.success('批量创作已启动');
+                this.selectedTopicIds = [];
+                await this.fetchTopics();
+            } catch (error) {
+                console.error('批量创作失败:', error);
+                this.$message.error(`批量创作失败: ${error.message}`);
+            }
         },
         async triggerOptimizeSelected() {
             if (!this.selectedTopicIds.length) return;
-            this.$message.success('批量优化已启动');
-            this.selectedTopicIds = [];
-            await this.fetchTopics();
+            try {
+                const token = localStorage.getItem('authToken');
+                if (!token) {
+                    this.$message.error('请先登录');
+                    return;
+                }
+                const response = await fetch('/api/system/optimize/run', {
+                    method: 'POST',
+                    headers: {
+                        'Authorization': 'Bearer ' + token,
+                        'Content-Type': 'application/json'
+                    },
+                    body: JSON.stringify({ topic_ids: this.selectedTopicIds })
+                });
+                if (!response.ok) {
+                    const errorData = await response.json().catch(() => ({}));
+                    throw new Error(errorData.detail || `请求失败: ${response.status}`);
+                }
+                const data = await response.json();
+                this.$message.success('批量优化完成');
+                this.selectedTopicIds = [];
+                await this.fetchTopics();
+            } catch (error) {
+                console.error('批量优化失败:', error);
+                this.$message.error(`批量优化失败: ${error.message}`);
+            }
         },
-        openPreview(topic) {
+        async openPreview(topic) {
             this.previewTopic = topic;
+            this.previewPlatform = 'zhihu';
             this.previewVisible = true;
+            this.platformContents = {};
+            // 并行加载所有平台内容
+            const token = localStorage.getItem('authToken');
+            if (!token) {
+                this.$message.warning('请先登录');
+                return;
+            }
+            const platforms = ['zhihu', 'wechat', 'xiaohongshu'];
+            const promises = platforms.map(p =>
+                fetch(`/api/articles/${topic.id}/preview?platform=${p}`, {
+                    headers: { 'Authorization': 'Bearer ' + token }
+                })
+                .then(r => r.ok ? r.json() : null)
+                .then(d => {
+                    if (d && d.html) {
+                        this.platformContents[p] = d.html;
+                    }
+                })
+                .catch(e => console.error(`加载${p}预览失败:`, e))
+            );
+            await Promise.all(promises);
+        },
+        getPreviewHtml(platform) {
+            return this.platformContents[platform] || '暂无内容';
+        },
+        platformName(platform) {
+            const names = {
+                zhihu: '知乎',
+                wechat: '微信公众号',
+                xiaohongshu: '小红书'
+            };
+            return names[platform] || platform;
         },
         copyContent(platform) {
             if (!this.previewTopic || !this.previewTopic.content) {
@@ -312,6 +406,7 @@ const TopicsApp = {
             });
         },
                 async createTopic(topic) {
+                    console.log('createTopic clicked, topic:', topic);
                     if (this.isStatus(topic, 'published')) {
                         this.$message.info('已发布选题不可创作');
                         return;
@@ -322,13 +417,13 @@ const TopicsApp = {
                             this.$message.error('请先登录');
                             return;
                         }
-                        const response = await fetch('/api/generate/run', {
+                        const response = await fetch('/api/system/generate/run', {
                             method: 'POST',
                             headers: {
                                 'Authorization': 'Bearer ' + token,
                                 'Content-Type': 'application/json'
                             },
-                            body: JSON.stringify({ topic_ids: [topic.id] })
+                            body: JSON.stringify({ topic_id: topic.id })
                         });
                         if (!response.ok) {
                             const errorData = await response.json().catch(() => ({}));
@@ -353,7 +448,7 @@ const TopicsApp = {
                             this.$message.error('请先登录');
                             return;
                         }
-                        const response = await fetch('/api/optimizer/run', {
+                        const response = await fetch('/api/system/optimize/run', {
                             method: 'POST',
                             headers: {
                                 'Authorization': 'Bearer ' + token,
@@ -433,6 +528,15 @@ const TopicsApp = {
             },
         handleLogout() { localStorage.removeItem('authToken'); window.location.href = '/'; },
         redirectToPage(page) { window.location.href = page.startsWith('/') ? page : '/' + page; },
+        getStatusLabel(status) {
+            const statusMap = {
+                'pending': '待处理',
+                'review': '待审查',
+                'ready': '待发布',
+                'published': '已发布'
+            };
+            return statusMap[status] || status;
+        },
         formatDate(dateStr) { 
             if (!dateStr) return '-';
             try {