feat: 新增参考材料前端 UI

- 在左侧片段选择卡片下方添加参考材料卡片
- 支持动态添加/删除参考材料
- 每个材料包含可选标题和内容输入
- 标题为空时自动显示为「参考材料{n}」
- 材料内容实时预览到 Prompt
- 草稿自动保存/加载包含材料数据
- 保存会话时支持保存材料

frontend/index.html

@@ -73,6 +73,17 @@
                 <div class="card-body" id="snippets-container"></div>
             </div>
 
+            <!-- 参考材料 -->
+            <div class="card">
+                <div class="card-header">
+                    📦 参考材料
+                    <button class="btn btn-sm" onclick="addMaterial()">+ 添加</button>
+                </div>
+                <div class="card-body" id="materials-container">
+                    <div class="text-sm text-muted" id="materials-empty">暂无参考材料</div>
+                </div>
+            </div>
+
             <!-- CLAUDE.md -->
             <div class="card">
                 <div class="collapse-header" onclick="toggleCollapse(this)">
@@ -173,6 +184,7 @@
         let allSnippets = [];
         let selectedTags = {}; // tagId -> optionId
         let selectedSnippets = []; // [{snippetId, sortOrder}]
+        let materials = []; // [{title, content}]
         let suggestions = [];
 
         // 初始化
@@ -380,6 +392,16 @@
                 }
             }
 
+            // Materials
+            const validMaterials = materials.filter(m => m.content.trim());
+            if (validMaterials.length > 0) {
+                const materialParts = validMaterials.map((m, i) => {
+                    const title = m.title.trim() || `参考材料${i + 1}`;
+                    return `--- ${title} ---\n${m.content}`;
+                });
+                parts.push(`## 参考材料\n\n${materialParts.join('\n\n')}`);
+            }
+
             // Suggestions
             const adoptedSuggestions = suggestions.filter(s => s.adopted);
             if (adoptedSuggestions.length > 0) {
@@ -441,6 +463,51 @@
         document.getElementById('tag-search')?.addEventListener('input', debounce(() => renderTags(), 300));
         document.getElementById('snippet-search')?.addEventListener('input', debounce(() => renderSnippets(), 300));
 
+        // 参考材料管理
+        function addMaterial() {
+            materials.push({ title: '', content: '' });
+            renderMaterials();
+            updatePreview();
+        }
+
+        function removeMaterial(index) {
+            materials.splice(index, 1);
+            renderMaterials();
+            updatePreview();
+        }
+
+        function renderMaterials() {
+            const container = document.getElementById('materials-container');
+            const emptyHint = document.getElementById('materials-empty');
+
+            if (materials.length === 0) {
+                container.innerHTML = '<div class="text-sm text-muted" id="materials-empty">暂无参考材料</div>';
+                return;
+            }
+
+            container.innerHTML = materials.map((m, i) => `
+                <div class="mb-3 p-3" style="background:var(--bg-tertiary);border-radius:8px">
+                    <div class="flex items-center justify-between mb-2">
+                        <input class="input" placeholder="参考材料${i + 1}" value="${escapeHtml(m.title)}"
+                            oninput="updateMaterialTitle(${i}, this.value)" style="flex:1;margin-right:8px">
+                        <button class="btn btn-sm" onclick="removeMaterial(${i})" style="color:var(--error-color)">✕</button>
+                    </div>
+                    <textarea class="textarea" placeholder="输入参考材料内容..." rows="3"
+                        oninput="updateMaterialContent(${i}, this.value)">${escapeHtml(m.content)}</textarea>
+                </div>
+            `).join('');
+        }
+
+        function updateMaterialTitle(index, title) {
+            materials[index].title = title;
+            updatePreview();
+        }
+
+        function updateMaterialContent(index, content) {
+            materials[index].content = content;
+            updatePreview();
+        }
+
         // 自定义输入变化时更新预览
         document.getElementById('custom-content')?.addEventListener('input', debounce(() => updatePreview(), 200));
         document.getElementById('project-name')?.addEventListener('input', debounce(() => updatePreview(), 200));
@@ -591,6 +658,14 @@
                 sort_order: s.sortOrder
             }));
 
+            const materialsData = materials
+                .filter(m => m.content.trim())
+                .map((m, i) => ({
+                    title: m.title.trim(),
+                    content: m.content,
+                    sort_order: i
+                }));
+
             try {
                 await API.post('/api/builder/sessions', {
                     title,
@@ -598,7 +673,8 @@
                     final_prompt: finalPrompt,
                     claude_session_id: claudeSessionId,
                     tag_option_ids: tagOptionIds,
-                    snippet_ids: snippetIds
+                    snippet_ids: snippetIds,
+                    materials: materialsData
                 });
                 closeSaveModal();
                 Toast.success('会话已保存');
@@ -616,6 +692,7 @@
                     claudeMD: document.getElementById('claude-md').value,
                     selectedTags: { ...selectedTags },
                     selectedSnippets: [...selectedSnippets],
+                    materials: materials.map(m => ({ title: m.title, content: m.content })),
                 });
             }, 1000);
 
@@ -633,6 +710,8 @@
             document.getElementById('claude-md').value = draft.claudeMD || '';
             selectedTags = draft.selectedTags || {};
             selectedSnippets = draft.selectedSnippets || [];
+            materials = draft.materials || [];
+            renderMaterials();
         }
 
         function resetBuilder() {
@@ -644,11 +723,13 @@
             document.getElementById('session-prompts').classList.add('hidden');
             selectedTags = {};
             selectedSnippets = [];
+            materials = [];
             suggestions = [];
             document.getElementById('suggestions-card').style.display = 'none';
             Draft.clear('builder');
             renderTags();
             renderSnippets();
+            renderMaterials();
             updatePreview();
             Toast.success('已重置');
         }