feat: KBDB-graph 插件獨立 — 全面改寫成走基本盤 API（API-as-Wall）

按 leo 鐵律（2026-06-14）把插件從「直接 SQL 操作基本盤表」改寫成
「只透過基本盤 arcrun/kbdb HTTP API 讀寫」。零建表、零 migration、零 SQL。

- 新增 src/lib/kbdb-client.ts：唯一對外通道，封裝 entries/templates/records API
- 新增 src/lib/templates.ts：triplet/entity template 定義（替代建表）
- 改寫 21 個違規 action（triplet/graph/entity/search）→ 走 client，圖在插件層記憶體組裝
- 移除所有 migrations、D1/Vectorize/AI 綁定；embedding/語意搜尋歸基本盤 optional 模組
- index.ts 只掛 triplets/graph/entities/search 路由；基本盤路由歸 arcrun/kbdb
- 測試改走 mock client（純 node）；裁剪 CLAUDE.md 只留 graph 插件 + 鐵律
- 修正 SDD design.md「讀現狀推翻鐵律」的錯誤判斷（共用 D1 → API-as-Wall）

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/triplet-crud.test.ts

@@ -0,0 +1,36 @@
+// triplet CRUD — 走 mock KbdbClient（API-as-Wall），零 SQL。
+import { describe, it, expect } from 'vitest';
+import { createTriplet, queryTriplets, getTriplet } from '../src/actions/triplet-crud';
+import { mockClient } from './mock-client';
+
+describe('createTriplet → records API', () => {
+  it('建立後可由 id 取回', async () => {
+    const c = mockClient();
+    const r = await createTriplet(c, { subject: 'InkStone', predicate: '是', object: '創業 OS' });
+    expect(r.id).toBeDefined();
+    expect(r.subject).toBe('InkStone');
+
+    const got = await getTriplet(c, r.id);
+    expect(got?.predicate).toBe('是');
+    expect(got?.object).toBe('創業 OS');
+  });
+});
+
+describe('queryTriplets → 插件層 filter', () => {
+  it('by subject 過濾', async () => {
+    const c = mockClient();
+    await createTriplet(c, { subject: 'KBDB', predicate: '使用', object: 'D1' });
+    await createTriplet(c, { subject: 'Other', predicate: '使用', object: 'X' });
+
+    const { triplets, count } = await queryTriplets(c, { subject: 'KBDB' });
+    expect(count).toBe(1);
+    expect(triplets[0].object).toBe('D1');
+  });
+
+  it('limit/offset 分頁', async () => {
+    const c = mockClient();
+    for (let i = 0; i < 5; i++) await createTriplet(c, { subject: `s${i}`, predicate: 'p', object: 'o' });
+    const { triplets } = await queryTriplets(c, { limit: 2, offset: 1 });
+    expect(triplets.length).toBe(2);
+  });
+});