feat: 知识库文档列表标题增加「清空」按钮——一键清空全部文档（分块与检索索引级联删除），清空前弹窗警告确认

ui/src/api.ts

@@ -526,6 +526,8 @@ export const api = {
   ) => invoke<KbImportResult[]>("kb_import_documents", { kbId, files }),
   removeKbDocument: (documentId: string) =>
     invoke<void>("remove_kb_document", { documentId }),
+  kbClearDocuments: (kbId: string) =>
+    invoke<number>("kb_clear_documents", { kbId }),
   kbRechunkDocument: (documentId: string) =>
     invoke<number>("kb_rechunk_document", { documentId }),
   kbSearch: (kbId: string | null, query: string, page?: number, pageSize?: number) =>

ui/src/pages/KnowledgeBasePage.tsx

@@ -253,6 +253,25 @@ export default function KnowledgeBasePage() {
     }
   }
 
+  async function handleClearDocs() {
+    if (!selected) return;
+    if (
+      !confirm(
+        `确定清空知识库「${selected.name}」的全部 ${docTotal} 个文档吗？\n\n此操作不可恢复，所有文档、分块与检索索引将一并删除。`,
+      )
+    ) {
+      return;
+    }
+    try {
+      const n = await api.kbClearDocuments(selected.id);
+      setMsg(`已清空 ${n} 个文档`);
+      await loadDocPage(selected.id, 1);
+      await refreshKbs();
+    } catch (e) {
+      setMsg(`清空失败：${String(e)}`);
+    }
+  }
+
   async function handleSearch(page = 1) {
     if (!query.trim()) return;
     setSearching(true);
@@ -553,8 +572,18 @@ export default function KnowledgeBasePage() {
 
             {/* 文档列表 */}
             <section className="mb-6">
-              <div className="mb-2 text-xs uppercase text-slate-500">
-                文档（共 {docTotal} 个）
+              <div className="mb-2 flex items-center justify-between">
+                <div className="text-xs uppercase text-slate-500">
+                  文档（共 {docTotal} 个）
+                </div>
+                {docTotal > 0 ? (
+                  <button
+                    className="rounded-lg border border-border bg-panel-2 px-2.5 py-1 text-xs text-slate-400 hover:text-red-400"
+                    onClick={handleClearDocs}
+                  >
+                    清空
+                  </button>
+                ) : null}
               </div>
               {docs.length === 0 ? (
                 <div className="rounded-xl border border-dashed border-border bg-panel/50 px-4 py-10 text-center text-sm text-slate-500">