feat(km-wiki-ingest): 重做成跑在 cypher 上的 workflow（走 cypher binding，汰換 service-binding drainer，D28）

把知識庫 ingest 從 standalone drainer（誤用 Service Bindings）重表達為 cypher workflow：

- workflow.yaml（Phase 0 cron drain）：watch_cron→load_cursor→list_cards→pick_card(code)
  →fetch_card→parse_card(code)→upsert_entry→save_cursor→post_envelopes→post_one_envelope。
  線性 pipe，跨-worker 全走 cypher binding（零件節點），零 service binding。
- workflow.delta.yaml（Gitea webhook 穩態）：collect_changed(code)→foreach card→fetch/parse/upsert/foreach envelope。
- code/kbdb/graph 接法：code=canonical `code` 零件（arcrun-code）；kbdb/graph=http_request 零件打
  /entries/ingest、/triplets/ingest（server 端冪等）；Gitea=http_request。
- 平台端最小補丁（各需 gated 部署）：
  1) cypher-executor component-loader：WASM_HTTP_RUNNER_IDS 加 'code'（canonical→arcrun-code，cypher binding 正解）。
  2) kbdb base：POST /entries/ingest（page_name+content_hash 冪等 upsert，對稱 graph /triplets/ingest；
     因 flow DSL 無資料條件分支，把 create/patch/skip 冪等推到 server 端）。
- drainer/DEPRECATED.md：標舊 standalone worker 退役計畫（新版穩定後 wrangler delete）。
- DEPLOY.md：部署順序、cron/webhook 掛法、subdomain 對齊、驗收與退役。

本輪不部署（待總管/leo 審架構）。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HJiLCRUU2o3aSpPEzVCt2o

kbdb/src/routes/entries.ts

@@ -23,6 +23,68 @@ entryRoutes.post('/', async (c) => {
   return c.json({ success: true, entry });
 });
 
+// POST /entries/ingest — server 端冪等 upsert（page_name 當鍵 + content_hash skip-if-unchanged）。
+//   語義對稱 graph 的 POST /triplets/ingest：讓「工作流只打一發、冪等由 server 保證」，
+//   使 km_wiki_ingest_drain cypher workflow 不必在 flow DSL 裡做 lookup→decide→create/patch 分支
+//   （DSL 無資料條件分支）。owner_id 走 query。body 收 parse_card 產的 entry 形狀：
+//     { page_name, entry_type, content, source, tags?(array|json), metadata?(object)|metadata_json?, content_hash? }
+//   行為：無此 (page_name,owner_id) → create；有且 content_hash 同 → skip（不重嵌）；有且不同/無 hash → update+重嵌。
+//   回：{ success, action:'created'|'updated'|'skipped', entry }。
+entryRoutes.post('/ingest', async (c) => {
+  const body = await c.req.json().catch(() => null) as Record<string, unknown> | null;
+  if (!body || !body.entry_type || !body.page_name) {
+    return c.json({ success: false, error: 'entry_type 與 page_name 必填' }, 400);
+  }
+  const owner_id = c.req.query('owner_id') || (body.owner_id as string | undefined) || undefined;
+  const page_name = String(body.page_name);
+
+  // 正規化 tags / metadata → *_json 字串（同時容忍呼叫端直接給 *_json）。
+  const tags_json =
+    typeof body.tags_json === 'string' ? body.tags_json
+    : Array.isArray(body.tags) ? JSON.stringify(body.tags)
+    : undefined;
+  const metaObj = (body.metadata && typeof body.metadata === 'object') ? body.metadata as Record<string, unknown> : undefined;
+  const metadata_json =
+    typeof body.metadata_json === 'string' ? body.metadata_json
+    : metaObj ? JSON.stringify(metaObj)
+    : undefined;
+  const newHash =
+    (typeof body.content_hash === 'string' && body.content_hash)
+    || (metaObj && typeof metaObj.content_hash === 'string' ? metaObj.content_hash : undefined);
+
+  // 查現有（page_name 是冪等鍵；owner_id 隔離租戶）。
+  const { entries } = await listEntries(c.env.DB, { page_name, owner_id, limit: 1 });
+  const existing = entries[0];
+
+  if (existing) {
+    let storedHash: string | undefined;
+    try { storedHash = existing.metadata_json ? (JSON.parse(existing.metadata_json).content_hash as string) : undefined; } catch { /* ignore */ }
+    if (newHash && storedHash && storedHash === newHash) {
+      return c.json({ success: true, action: 'skipped', entry: existing });
+    }
+    const entry = await updateEntry(c.env.DB, existing.id, {
+      content: body.content as string | undefined,
+      ...(tags_json !== undefined ? { tags_json } : {}),
+      ...(metadata_json !== undefined ? { metadata_json } : {}),
+    });
+    if (embedEnabled(c.env) && body.content !== undefined && entry) {
+      c.executionCtx.waitUntil(embedOnWrite(c.env, entry).catch(() => {}));
+    }
+    return c.json({ success: true, action: 'updated', entry });
+  }
+
+  const entry = await createEntry(c.env.DB, {
+    entry_type: String(body.entry_type),
+    content: body.content as string | undefined,
+    owner_id,
+    page_name,
+    tags_json,
+    metadata_json,
+  });
+  if (embedEnabled(c.env)) c.executionCtx.waitUntil(embedOnWrite(c.env, entry).catch(() => {}));
+  return c.json({ success: true, action: 'created', entry });
+});
+
 // GET /entries — list with filters (entry_type, owner_id, parent_id, page_name, source, q/search)
 // e.g. list workflows under a project: ?parent_id=PROJECT&entry_type=workflow
 // e.g. get one by idempotency key: ?page_name=skill-rag_with_arcrun