feat: structure view in dashboard and settings persistence

- Add GET /api/claude/sessions/{session_id}/builder API for structure view
- Load builder session tags and snippets by Claude session ID
- Implement structure view in dashboard: shows tag selections and snippet details
- Add LoadSettings to persist LLM config changes across restarts
- Settings are now loaded from database on startup

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/dashboard.html

@@ -162,7 +162,6 @@
         }
 
         function renderPromptCard(prompt, index) {
-            const preview = truncateText(prompt.prompt, 150);
             return `
                 <div class="card">
                     <div class="card-header">
@@ -176,7 +175,7 @@
                             ${renderPromptContent(prompt.prompt)}
                         </div>
                         <div id="prompt-struct-${index}" class="prompt-struct-view hidden">
-                            <div class="text-sm text-muted">结构视图暂不可用（需要关联构建会话数据）</div>
+                            <div class="text-sm text-muted" id="struct-content-${index}">加载中...</div>
                         </div>
                     </div>
                 </div>
@@ -227,7 +226,7 @@
             return parts.length > 0 ? parts.join('') : `<div style="white-space:pre-wrap">${escapeHtml(text)}</div>`;
         }
 
-        function togglePromptView(index) {
+        async function togglePromptView(index) {
             const textView = document.getElementById(`prompt-text-${index}`);
             const structView = document.getElementById(`prompt-struct-${index}`);
             const btn = document.getElementById(`view-btn-${index}`);
@@ -240,6 +239,58 @@
                 textView.classList.add('hidden');
                 structView.classList.remove('hidden');
                 btn.textContent = '切换到文本视图';
+                // Load structure view data
+                await loadStructureView(index);
+            }
+        }
+
+        async function loadStructureView(index) {
+            const container = document.getElementById(`struct-content-${index}`);
+            if (container.dataset.loaded) return;
+
+            try {
+                const data = await API.get(`/api/claude/sessions/${currentSession}/builder`);
+                if (!data || !data.session) {
+                    container.innerHTML = '<div class="text-sm text-muted">未找到关联的构建会话</div>';
+                    container.dataset.loaded = 'true';
+                    return;
+                }
+
+                let html = '';
+
+                // Tags
+                if (data.tags && data.tags.length > 0) {
+                    html += '<div class="mb-3"><div class="text-sm font-medium mb-2">🏷️ 标签选择</div>';
+                    html += data.tags.map(t => `
+                        <div class="mb-2 p-2" style="background:var(--bg-tertiary);border-radius:6px">
+                            <div class="text-sm font-medium">${escapeHtml(t.tag_name)}</div>
+                            <div class="text-xs text-muted mt-1">选项: ${escapeHtml(t.option_label)}</div>
+                            <div class="text-xs mt-1" style="color:var(--text-secondary)">${escapeHtml(t.constraint_text)}</div>
+                        </div>
+                    `).join('');
+                    html += '</div>';
+                }
+
+                // Snippets
+                if (data.snippets && data.snippets.length > 0) {
+                    html += '<div class="mb-3"><div class="text-sm font-medium mb-2">📄 片段</div>';
+                    html += data.snippets.map(s => `
+                        <div class="mb-2 p-2" style="background:var(--bg-tertiary);border-radius:6px">
+                            <div class="text-sm font-medium">${escapeHtml(s.name)} <span class="text-xs text-muted">(${escapeHtml(s.category)})</span></div>
+                            <div class="text-xs mt-1" style="color:var(--text-secondary);white-space:pre-wrap">${escapeHtml(s.content.substring(0, 200))}${s.content.length > 200 ? '...' : ''}</div>
+                        </div>
+                    `).join('');
+                    html += '</div>';
+                }
+
+                if (!html) {
+                    html = '<div class="text-sm text-muted">无标签和片段数据</div>';
+                }
+
+                container.innerHTML = html;
+                container.dataset.loaded = 'true';
+            } catch (e) {
+                container.innerHTML = '<div class="text-sm text-muted">加载结构视图失败</div>';
             }
         }