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>

src/actions/triplet-crud.ts

@@ -0,0 +1,90 @@
+// 三元組 CRUD — 走基本盤 API（API-as-Wall，零 SQL）
+// 寫 triplet = 確保 template='triplet' + POST /records 填 slot。
+// 查 triplet = GET /records/by-template/triplet → 插件層 filter/組裝。
+
+import type { Triplet } from '../types';
+import type { KbdbClient } from '../lib/kbdb-client';
+import { TPL_TRIPLET, ensurePluginTemplates, recordToTriplet } from '../lib/templates';
+import { classifyClusters } from './triplet-cluster';
+
+export type CreateTripletData = {
+  subject: string;
+  predicate: string;
+  object: string;
+  source_block_id?: string;
+  confidence?: number;
+  owner_id?: string;
+  clusters?: string[];
+  bridge_score?: number;
+  subject_entity_type?: string;
+  object_entity_type?: string;
+};
+
+/** 建立三元組 → POST /records（template=triplet）。 */
+export async function createTriplet(
+  client: KbdbClient,
+  data: CreateTripletData,
+): Promise<{ id: string; subject: string; predicate: string; object: string }> {
+  await ensurePluginTemplates(client);
+
+  const clusters = data.clusters ?? [];
+  const bridgeScore = data.bridge_score ?? Math.max(0, clusters.length - 1);
+
+  const values: Record<string, string> = {
+    subject: data.subject,
+    predicate: data.predicate,
+    object: data.object,
+    confidence: String(data.confidence ?? 1.0),
+    clusters_json: JSON.stringify(clusters),
+    bridge_score: String(bridgeScore),
+  };
+  if (data.source_block_id) values.source_block_id = data.source_block_id;
+  if (data.subject_entity_type) values.subject_entity_type = data.subject_entity_type;
+  if (data.object_entity_type) values.object_entity_type = data.object_entity_type;
+
+  const id = await client.createRecord(TPL_TRIPLET, values, data.owner_id);
+  return { id, subject: data.subject, predicate: data.predicate, object: data.object };
+}
+
+export type TripletFilters = {
+  subject?: string;
+  predicate?: string;
+  object?: string;
+  limit?: number;
+  offset?: number;
+  owner_id?: string;
+  entity_type?: string;
+};
+
+/** 查三元組 → 取 template 全部 record，插件層 filter（base 無複合 slot 查詢）。 */
+export async function queryTriplets(
+  client: KbdbClient,
+  filters: TripletFilters,
+): Promise<{ triplets: Triplet[]; count: number }> {
+  const records = await client.listRecordsByTemplate(TPL_TRIPLET, filters.owner_id);
+  let triplets = records.map(recordToTriplet);
+
+  if (filters.subject) triplets = triplets.filter((t) => t.subject === filters.subject);
+  if (filters.predicate) triplets = triplets.filter((t) => t.predicate === filters.predicate);
+  if (filters.object) triplets = triplets.filter((t) => t.object === filters.object);
+  if (filters.entity_type) {
+    triplets = triplets.filter(
+      (t) => t.subject_entity_type === filters.entity_type || t.object_entity_type === filters.entity_type,
+    );
+  }
+
+  const offset = filters.offset ?? 0;
+  const limit = Math.min(filters.limit ?? 50, 2000);
+  const page = triplets.slice(offset, offset + limit);
+  return { triplets: page, count: page.length };
+}
+
+/** 取單一三元組 → GET /records/:id。 */
+export async function getTriplet(client: KbdbClient, id: string): Promise<Triplet | null> {
+  const rec = await client.getRecord(id);
+  if (!rec) return null;
+  return recordToTriplet({ ...rec, template: TPL_TRIPLET });
+}
+
+// re-export clusters helper（AI 分群，純函式 + 走 client 無關）
+export { classifyClusters };