feat: 知识库设置页面增加 retrieval_model 检索配置功能

1. 召回测试页面增加 Score 阈值参数配置
2. 知识库设置页面新增检索模型配置:
   - 检索方式 (向量/全文/混合/关键字检索)
   - Reranking 模型 (默认开启，不可关闭)
   - Top K 返回数量
   - Score 阈值 (默认开启，可调节数值)
3. 修复 Dify API 字段名问题 (retrieval_model_dict)
4. 优化数据加载流程，使用详情接口获取完整配置

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/routes/api.dataset.datasets.$datasetId.tsx

@@ -54,15 +54,22 @@ export async function loader({ request, params }: LoaderFunctionArgs) {
 }
 
 /**
- * PATCH /api/dataset/datasets/:datasetId - 修改知识库名称
+ * PATCH /api/dataset/datasets/:datasetId - 修改知识库设置
  *
  * Dify API: PATCH /datasets/{dataset_id}
  *
- * 请求体: { "name": "新的知识库名称" }
+ * 请求体支持以下字段:
+ * - name (string): 知识库名称（必填）
+ * - retrieval_model (object): 检索模型配置（选填）
+ *   - search_method: 'keyword_search' | 'semantic_search' | 'full_text_search' | 'hybrid_search'
+ *   - reranking_enable: boolean
+ *   - reranking_model: { reranking_provider_name, reranking_model_name }
+ *   - weights: number | null (混合检索的语义权重)
+ *   - top_k: number
+ *   - score_threshold_enabled: boolean
+ *   - score_threshold: number | null
  *
- * 注意：
- * - 仅允许修改知识库名称，其他字段不开放修改
- * - 删除知识库功能不对外开放
+ * 注意：删除知识库功能不对外开放
  */
 export async function action({ request, params }: ActionFunctionArgs) {
     try {
@@ -89,7 +96,7 @@ export async function action({ request, params }: ActionFunctionArgs) {
         if (method === 'PATCH') {
             const body = await request.json();
 
-            // 只允许修改 name 字段
+            // name 是必填字段
             if (!body.name || typeof body.name !== 'string') {
                 return new Response(
                     JSON.stringify({ error: '请提供有效的知识库名称 (name)' }),
@@ -97,17 +104,48 @@ export async function action({ request, params }: ActionFunctionArgs) {
                 );
             }
 
-            // 只传递 name 字段，忽略其他字段
-            const allowedBody = { name: body.name.trim() };
-
-            if (allowedBody.name.length === 0) {
+            const trimmedName = body.name.trim();
+            if (trimmedName.length === 0) {
                 return new Response(
                     JSON.stringify({ error: '知识库名称不能为空' }),
                     { status: 400, headers: { 'Content-Type': 'application/json' } }
                 );
             }
 
-            console.log('[API] Update Dataset Name:', { datasetId, name: allowedBody.name });
+            // 构建允许的请求体
+            const allowedBody: Record<string, any> = {
+                name: trimmedName,
+            };
+
+            // 可选: retrieval_model 检索模型配置
+            if (body.retrieval_model && typeof body.retrieval_model === 'object') {
+                const rm = body.retrieval_model;
+
+                // 验证 search_method
+                const validSearchMethods = ['keyword_search', 'semantic_search', 'full_text_search', 'hybrid_search'];
+                if (rm.search_method && !validSearchMethods.includes(rm.search_method)) {
+                    return new Response(
+                        JSON.stringify({ error: '无效的检索方法 (search_method)' }),
+                        { status: 400, headers: { 'Content-Type': 'application/json' } }
+                    );
+                }
+
+                allowedBody.retrieval_model = {
+                    search_method: rm.search_method,
+                    reranking_enable: rm.reranking_enable ?? false,
+                    reranking_mode: rm.reranking_mode ?? null,
+                    reranking_model: rm.reranking_model ?? {
+                        reranking_provider_name: '',
+                        reranking_model_name: '',
+                    },
+                    weights: rm.weights ?? null,
+                    top_k: rm.top_k ?? 3,
+                    score_threshold_enabled: rm.score_threshold_enabled ?? false,
+                    score_threshold: rm.score_threshold_enabled ? (rm.score_threshold ?? null) : null,
+                };
+            }
+
+            console.log('[API] Update Dataset Settings:', { datasetId, body: allowedBody });
 
             const apiUrl = `${API_BASE_URL}/dify_dataset/datasets/${datasetId}`;
             const response = await fetch(apiUrl, {