feat(graph): owner_id 寫入鏈必經(根治無主資料)——配合 base owner-mandatory(D28)

- kbdb-client requireOwner 守衛:漏 owner 插件端即 throw,不再靜默送 owner:''
- owner 一路 thread:persistNodes/ingestEnvelope/entity-crud/triplet-crud 全必填
- 病灶修:POST /triplets/ingest 原本沒傳 owner→加 owner_id query+400
- 寫入 route 缺 owner→400;vitest 23→27
- 註:gloss-bridge 分支的 backfill/gloss-entry 另需套 owner 必填(附說明),不跨支疊改

src/actions/entity-normalize.ts

@@ -18,7 +18,7 @@ import type { KbdbClient } from '../lib/kbdb-client';
 export async function normalizeEntity(
   client: KbdbClient,
   rawName: string,
-  owner?: string,
+  owner: string,  // 必經：未命中會建新 entity，必帶 owner
 ): Promise<string> {
   try {
     const exact = await findEntityByName(client, rawName, owner);