feat(api): embed slots with ov replica and public feed

Co-Authored-By: Claude Code <noreply@anthropic.com>

services/sync/src/sender.ts

@@ -188,8 +188,8 @@ export class OutboxSender {
 
   /**
    * outbox 行 → SyncEvent 线格式。entityId 按实体类型取自不同位置：
-   * album → albumId 列；photo → photoId 列；category/asset → 载荷内的
-   * categoryId/assetId（outbox 表无此二列）。映射缺料抛错（fail-fast：
+   * album → albumId 列；photo → photoId 列；category/asset/slot-state → 载荷内
+   * 的 categoryId/assetId/slotId（outbox 表无此三列）。映射缺料抛错（fail-fast：
    * 本轮不推、不标记，错误日志暴露；cn 侧发射器按构造保证不缺料）。
    */
   private toWireEvent(row: OutboxRow): SyncEventWire {
@@ -204,6 +204,11 @@ export class OutboxSender {
         throw new Error(`outbox 事件 ${row.id}（${type}）缺 photoId，无法推导 entityId`);
       }
       entityId = row.photoId;
+    } else if (entityType === 'slot-state') {
+      if (typeof payload.slotId !== 'string') {
+        throw new Error(`outbox 事件 ${row.id}（${type}）载荷缺 slotId，无法推导 entityId`);
+      }
+      entityId = payload.slotId;
     } else if (typeof payload.categoryId === 'string') {
       entityId = payload.categoryId;
     } else if (typeof payload.assetId === 'string') {