Revert "WIP(kbdb): 語意搜尋零命中的排查——⚠️ 被總管中途叫停，未完成驗證"

This reverts commit af3edff856.

kbdb/tests/search-semantic-empty-reason.test.ts

@@ -107,80 +107,3 @@ describe('GET /entries/search?mode=semantic — 零命中時分辨「為什麼
     expect(body.capability_hint).toBeUndefined();
   });
 });
-
-// ── 第四態 filter_blind（Arcrun#85 D70，2026-08-11 leo21c 實撞）─────────────────
-//
-// 現場：現役 Vectorize index `arcrun-kbdb-embed-m3` 上**一個 metadata index 都沒有**
-// （真兇＝arcrun-rag 安裝器把端點寫成 `metadata-index/create`，連字號版 CF 回 404，
-//   底線 `metadata_index/create` 才是對的；而該安裝器把失敗降級成一行 ⚠ 就宣告成功）。
-// ⇒ Vectorize 對 owner_id 下 filter 一律回 0 筆，而**每一條真實使用者路徑都帶 owner_id**
-//   做租戶隔離 ⇒ 語意搜尋 100% 全盲。
-// 實測（leo21c，同一句查詢）：不帶 filter → 1 命中 score 0.8957；帶 owner_id → 0 命中。
-//
-// 舊行為把這個歸成 no_match，回「換個說法或更具體的關鍵字再試試看」
-// ＝**把系統故障說成使用者的問題**，正是 leo 2026-08-09 直令禁止的那件事，
-// 而且沒有人會因為「搜不到」去翻 Cloudflare 的 Vectorize 設定。
-function makeFilterAwareEnv(
-  dbOpts: Parameters<typeof makeFakeDB>[0],
-  opts: { unfiltered: { id: string; score: number }[]; filtered: { id: string; score: number }[] },
-): Bindings {
-  return {
-    DB: makeFakeDB(dbOpts),
-    ENVIRONMENT: 'test',
-    AI: { async run() { return { data: [[0.1, 0.2, 0.3]] }; } },
-    VECTORIZE: {
-      async query(_v: number[], o?: { filter?: Record<string, unknown> }) {
-        const filtered = !!(o?.filter && Object.keys(o.filter).length > 0);
-        return { matches: filtered ? opts.filtered : opts.unfiltered };
-      },
-    },
-  } as unknown as Bindings;
-}
-
-describe('empty_reason=filter_blind — Vectorize metadata 過濾整個是死的', () => {
-  it('帶 owner_id 零命中、拿掉 filter 有命中 → filter_blind，且照實說是我們的故障', async () => {
-    const app = makeApp();
-    const env = makeFilterAwareEnv(
-      { embeddedCount: 805, hydrateEntry: mkEntry('e1') },
-      { unfiltered: [{ id: 'e1', score: 0.8957 }], filtered: [] },
-    );
-    const res = await app.request('/entries/search?q=黑面琵鷺&mode=semantic&owner_id=bfezv28v', {}, env);
-    const body = (await res.json()) as Record<string, unknown>;
-    expect(body.count).toBe(0);
-    expect(body.empty_reason).toBe('filter_blind');
-    const hint = body.capability_hint as string;
-    // 🔴 誠實鐵律：是故障、不是使用者的錯，且**明說換個說法沒有用**
-    expect(hint).toContain('故障');
-    expect(hint).toContain('不是你');
-    expect(/換個說法也不會有用/.test(hint)).toBe(true);
-    // 🔴 人話紅線：不准把 Vectorize/owner_id 這類內部詞漏給使用者
-    expect(/vectorize|owner_id|metadata|index/i.test(hint)).toBe(false);
-    // 技術細節與**處方順序**留給維運者
-    const admin = body.admin_hint as string;
-    expect(admin).toContain('metadata index');
-    expect(admin).toContain('reindex');
-  });
-
-  it('沒帶任何 filter 的查詢不做探針，維持 no_match（不多花一次查詢）', async () => {
-    const app = makeApp();
-    let queries = 0;
-    const env = {
-      DB: makeFakeDB({ embeddedCount: 42 }),
-      ENVIRONMENT: 'test',
-      AI: { async run() { return { data: [[0.1, 0.2, 0.3]] }; } },
-      VECTORIZE: { async query() { queries++; return { matches: [] }; } },
-    } as unknown as Bindings;
-    const res = await app.request('/entries/search?q=x&mode=semantic', {}, env);
-    const body = (await res.json()) as Record<string, unknown>;
-    expect(body.empty_reason).toBe('no_match');
-    expect(queries).toBe(1);
-  });
-
-  it('帶 filter 但拿掉 filter 也零命中 → 仍是 no_match（別把正常的找不到誣賴成故障）', async () => {
-    const app = makeApp();
-    const env = makeFilterAwareEnv({ embeddedCount: 42 }, { unfiltered: [], filtered: [] });
-    const res = await app.request('/entries/search?q=x&mode=semantic&owner_id=t1', {}, env);
-    const body = (await res.json()) as Record<string, unknown>;
-    expect(body.empty_reason).toBe('no_match');
-  });
-});