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/graph.test.ts

@@ -0,0 +1,47 @@
+// graph 查詢 — 圖在插件層記憶體組裝（不靠 DB VIEW），走 mock client。
+import { describe, it, expect } from 'vitest';
+import { createTriplet } from '../src/actions/triplet-crud';
+import { listNodes, getNodeEdges, getNeighbors } from '../src/actions/graph-nodes';
+import { findShortestPath } from '../src/actions/graph-path';
+import { mockClient } from './mock-client';
+import type { KbdbClient } from '../src/lib/kbdb-client';
+
+async function seed(c: KbdbClient) {
+  // A — B — C，D 孤立連 A
+  await createTriplet(c, { subject: 'A', predicate: 'r', object: 'B' });
+  await createTriplet(c, { subject: 'B', predicate: 'r', object: 'C' });
+  await createTriplet(c, { subject: 'A', predicate: 'r', object: 'D' });
+}
+
+describe('graph-nodes', () => {
+  it('listNodes 統計 edge_count', async () => {
+    const c = mockClient();
+    await seed(c);
+    const nodes = await listNodes(c, {});
+    const a = nodes.find((n) => n.node === 'A');
+    expect(a?.edge_count).toBe(2);
+  });
+
+  it('getNeighbors 收鄰居', async () => {
+    const c = mockClient();
+    await seed(c);
+    const neighbors = await getNeighbors(c, 'A');
+    expect(neighbors.sort()).toEqual(['B', 'D']);
+  });
+
+  it('getNodeEdges 取邊', async () => {
+    const c = mockClient();
+    await seed(c);
+    const edges = await getNodeEdges(c, 'B');
+    expect(edges.length).toBe(2);
+  });
+});
+
+describe('graph-path', () => {
+  it('A→C 最短路經過 B', async () => {
+    const c = mockClient();
+    await seed(c);
+    const res = await findShortestPath(c, 'A', 'C');
+    expect(res.path).toEqual(['A', 'B', 'C']);
+  });
+});