feat(ingest): T0.5–T5 純餵食器管線實作（issue #2）

ingest 全管線（採取優先、extract fallback、跨庫織網、POST envelope）：
- T0.5 骨架：Hono + zod-openapi，無 D1/Vectorize/AI 綁定（不碰儲存鐵律）
- T1 SourceAdapter：GitHub runtime API 拉 + per-file sha256 content-hash + /refresh 受理端
- T2 採取（路徑 A 優先）：harvest template 1.8.0+ 卡（gloss/實體/typed-edge）
- T3 extract（路徑 B fallback）：LlmCaller 可選模型 + JSON-fail 升級閘 + 端點對齊硬自檢護欄；第一版不 embed（只打標）
- T4 跨庫織網（主職）：匯總多 repo → 偵測跨庫橋/異見，不算 bridge_score（graph 領域）
- T5 輸出：buildEnvelope strict + 顯式禁送欄位自檢；graph-client 純 POST（cherry-pick _kbdb_client.py 改不碰 base）；薄 ops CLI（不帶查詢 MCP）

envelope 對齊 full contract（embed/id/aliases/predicate_embed）；同步 contract 向量化欄位升格。

gate：vitest 28 passed / tsc clean / wrangler dry-run 乾淨（只 env-var 綁定）。
端到端 ingest→graph：graph receiver 已補對齊 → 待 ingest 部署 + GRAPH_BASE_URL → 待部署驗，未假綠。

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

tests/graph-client.test.ts

@@ -0,0 +1,43 @@
+import { describe, it, expect } from 'vitest';
+import { makeGraphClient } from '../src/lib/graph-client';
+import type { Envelope } from '../src/types';
+
+const env: Envelope = {
+  source: { uri: 'github:o/r@a.md', content_hash: 'abc' },
+  extractor: { model: 'local-harvest', tier: 'shallow' },
+  triplets: [{ subject: 'A', predicate: 'p', object: 'B' }],
+};
+
+function mockFetch(status: number, body: unknown): typeof fetch {
+  return (async () =>
+    new Response(JSON.stringify(body), { status, headers: { 'Content-Type': 'application/json' } })) as any;
+}
+
+describe('makeGraphClient', () => {
+  it('GRAPH_BASE_URL 未設 → 誠實回 ok:false，不假綠、不打網路', async () => {
+    let called = false;
+    const client = makeGraphClient(undefined, undefined, (async () => {
+      called = true;
+      return new Response('{}');
+    }) as any);
+    const r = await client.postEnvelope(env);
+    expect(r.ok).toBe(false);
+    expect(r.error).toContain('未設');
+    expect(called).toBe(false);
+  });
+
+  it('200 → ok + 帶 graph 回的 {skipped,ingested,deprecated}', async () => {
+    const client = makeGraphClient('https://graph.example', 'tok', mockFetch(200, { skipped: false, ingested: 1, deprecated: 0 }));
+    const r = await client.postEnvelope(env);
+    expect(r.ok).toBe(true);
+    expect((r.body as any).ingested).toBe(1);
+  });
+
+  it('422 → ok:false 帶 issues（供修禁送欄位）', async () => {
+    const client = makeGraphClient('https://graph.example', undefined, mockFetch(422, { error: 'invalid envelope', issues: [{ path: ['bridge_score'] }] }));
+    const r = await client.postEnvelope(env);
+    expect(r.ok).toBe(false);
+    expect(r.status).toBe(422);
+    expect((r.body as any).issues).toBeDefined();
+  });
+});