feat: 知识库管理界面（入库监控 + 检索台）

桌面端「知识库」模块从占位变为可用：入库(切块/embedding/Milvus 监控) +
检索调试台(向量召回，带分数与来源)。

- mcp-go: 新工具 kb_search(返回结构化 JSON [{text,score}])；rag.Hit 加 json 标签
- gateway: POST /api/v1/kb/search → kb_search（结构化命中给检索台）
- desktop: lib/api ingestKb/searchKb；新 KbView(左 入库+监控日志 / 右 检索台命中列表
  带 Milvus 来源徽标+分数)；App 接 kb 视图；LeftNav 知识库 ready
- 验证: gateway/mcp-go build✓ + e2e PASS + 前端 build✓；真实浏览器——入库3条→监控
  '已入库3块'；语义查询'存储和搜索向量的组件'→Milvus(0.612)>Neo4j>NATS 排序正确,
  全走真实百炼 embedding(控制面下发)+Milvus

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

sundynix-desktop/frontend/src/views/KbView.tsx

@@ -0,0 +1,144 @@
+import { useState } from "react";
+import { ingestKb, searchKb, type KbHit } from "../lib/api";
+
+interface IngestLog {
+  t: string;
+  msg: string;
+  ok: boolean;
+}
+
+// 知识库管理：入库监控（切块/embedding/Milvus）+ 检索调试台（带分数与来源）。
+export function KbView() {
+  const [kb, setKb] = useState("docs");
+  const [text, setText] = useState("");
+  const [logs, setLogs] = useState<IngestLog[]>([]);
+  const [ingesting, setIngesting] = useState(false);
+
+  const [q, setQ] = useState("");
+  const [topK, setTopK] = useState(5);
+  const [hits, setHits] = useState<KbHit[] | null>(null);
+  const [searching, setSearching] = useState(false);
+  const [err, setErr] = useState("");
+
+  const stamp = () => new Date().toLocaleTimeString();
+
+  const onIngest = async () => {
+    if (!text.trim()) return;
+    setIngesting(true);
+    try {
+      const msg = await ingestKb(kb, text);
+      setLogs((l) => [{ t: stamp(), msg, ok: true }, ...l]);
+      setText("");
+    } catch (e) {
+      setLogs((l) => [{ t: stamp(), msg: (e as Error).message, ok: false }, ...l]);
+    } finally {
+      setIngesting(false);
+    }
+  };
+
+  const onSearch = async () => {
+    if (!q.trim()) return;
+    setSearching(true);
+    setErr("");
+    try {
+      setHits(await searchKb(kb, q, topK));
+    } catch (e) {
+      setErr((e as Error).message);
+      setHits(null);
+    } finally {
+      setSearching(false);
+    }
+  };
+
+  return (
+    <div className="flex h-full flex-col">
+      <div className="flex items-center gap-2 border-b bg-white px-4 py-2">
+        <span className="text-sm font-semibold text-gray-700">知识库</span>
+        <input
+          className="w-40 rounded border px-2 py-1 text-sm"
+          value={kb}
+          onChange={(e) => setKb(e.target.value)}
+          placeholder="知识库名"
+          title="知识库（Milvus kb 字段分区）"
+        />
+        <span className="text-[11px] text-gray-400">入库 → 切块 / embedding / Milvus；检索 → 向量召回</span>
+      </div>
+
+      <div className="flex min-h-0 flex-1">
+        {/* 左：入库 + 监控日志 */}
+        <section className="flex w-1/2 flex-col border-r p-4">
+          <h3 className="mb-2 text-xs font-semibold text-gray-600">入库（按行切块）</h3>
+          <textarea
+            className="h-40 w-full resize-none rounded border p-2 text-sm"
+            value={text}
+            onChange={(e) => setText(e.target.value)}
+            placeholder={"每行一条知识，例如：\nsundynix 用 Milvus 做向量库\nsundynix 用 NATS 做消息总线"}
+          />
+          <button
+            onClick={onIngest}
+            disabled={ingesting || !text.trim()}
+            className="mt-2 self-start rounded bg-emerald-600 px-3 py-1 text-sm text-white disabled:opacity-40"
+          >
+            {ingesting ? "入库中…" : "⬆ 入库"}
+          </button>
+          <h3 className="mb-1 mt-4 text-xs font-semibold text-gray-600">入库监控</h3>
+          <ul className="flex-1 space-y-1 overflow-auto">
+            {logs.length === 0 && <li className="text-xs text-gray-400">尚无入库记录。</li>}
+            {logs.map((l, i) => (
+              <li key={i} className={`text-xs ${l.ok ? "text-emerald-700" : "text-rose-600"}`}>
+                <span className="text-gray-400">{l.t}</span> {l.ok ? "✓" : "✗"} {l.msg}
+              </li>
+            ))}
+          </ul>
+        </section>
+
+        {/* 右：检索调试台 */}
+        <section className="flex w-1/2 flex-col p-4">
+          <h3 className="mb-2 text-xs font-semibold text-gray-600">检索调试台（向量召回）</h3>
+          <div className="flex gap-2">
+            <input
+              className="flex-1 rounded border px-2 py-1 text-sm"
+              value={q}
+              onChange={(e) => setQ(e.target.value)}
+              onKeyDown={(e) => e.key === "Enter" && onSearch()}
+              placeholder="输入查询，语义召回相关片段…"
+            />
+            <input
+              type="number"
+              className="w-16 rounded border px-2 py-1 text-sm"
+              value={topK}
+              min={1}
+              max={20}
+              onChange={(e) => setTopK(Number(e.target.value))}
+              title="TopK"
+            />
+            <button
+              onClick={onSearch}
+              disabled={searching || !q.trim()}
+              className="rounded bg-violet-600 px-3 py-1 text-sm text-white disabled:opacity-40"
+            >
+              {searching ? "检索中…" : "检索"}
+            </button>
+          </div>
+          {err && <p className="mt-2 text-xs text-rose-600">✗ {err}</p>}
+          <ul className="mt-3 flex-1 space-y-2 overflow-auto">
+            {hits === null && <li className="text-xs text-gray-400">输入查询后展示命中片段与分数。</li>}
+            {hits !== null && hits.length === 0 && (
+              <li className="text-xs text-gray-400">无命中（知识库为空或 RAG 未配置）。</li>
+            )}
+            {hits?.map((h, i) => (
+              <li key={i} className="rounded border bg-gray-50 p-2">
+                <div className="mb-1 flex items-center gap-2 text-[10px]">
+                  <span className="rounded bg-sky-100 px-1.5 py-0.5 text-sky-700">Milvus 向量</span>
+                  <span className="text-gray-400">#{i + 1}</span>
+                  <span className="ml-auto font-mono text-violet-600">{h.score.toFixed(3)}</span>
+                </div>
+                <div className="text-xs text-gray-800">{h.text}</div>
+              </li>
+            ))}
+          </ul>
+        </section>
+      </div>
+    </div>
+  );
+}