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

tests/mock-client.ts

@@ -15,6 +15,8 @@ export class MockKbdbClient {
   }
 
   async createEntry(input: any): Promise<BaseEntry> {
+    // 對齊基本盤 D27/D28 即將上線的 owner 必填：缺 owner → 400（模擬 base 擋死無主寫入）。
+    if (!(input?.owner_id ?? '').trim()) throw new Error('[kbdb-base] POST /entries: owner_id required (400)');
     const id = this.id('entry');
     const entry: BaseEntry = { id, content: input.content ?? null, entry_type: input.entry_type, owner_id: input.owner_id ?? null };
     this.entries.set(id, entry);
@@ -61,6 +63,8 @@ export class MockKbdbClient {
   }
 
   async createRecord(template: string, values: Record<string, string>, owner_id?: string): Promise<string> {
+    // 對齊基本盤 D27/D28 即將上線的 owner 必填：缺 owner → 400（模擬 base 擋死無主寫入）。
+    if (!(owner_id ?? '').trim()) throw new Error('[kbdb-base] POST /records: owner_id required (400)');
     const id = this.id('rec');
     this.records.set(id, { template, values: { ...values }, owner_id });
     return id;