refactor(shared-ts,iam,core-edu,content,msg): remove outbox polling publisher

M8: Debezium CDC now handles outbox table to Kafka (ADR-032)

- Remove OutboxPublisher class from shared-ts

- Remove publisher from iam/core-edu/content/msg lifecycle and modules

- OutboxService retained for transactional outbox table writes

- Debezium monitors binlog and pushes to Kafka automatically

services/iam/src/app.module.ts

@@ -15,11 +15,7 @@ import { GraphqlModule } from "./graphql/graphql.module.js";
 import { RouterAuthGuard } from "./graphql/router-auth.guard.js";
 import { OutboxModule } from "@edu/shared-ts/outbox";
 import { getDbInstance } from "./config/database.js";
-import {
-  getKafkaProducer,
-  connectKafkaProducer,
-  IAM_KAFKA_TOPICS,
-} from "./config/kafka.js";
+import { connectKafkaProducer, IAM_KAFKA_TOPICS } from "./config/kafka.js";
 
 /**
  * IAM 根模块（v2.1）。
@@ -42,13 +38,9 @@ import {
       config: {
         tableName: "iam_outbox",
         kafkaTopic: IAM_KAFKA_TOPICS.USER_EVENTS,
-        pollIntervalMs: 1000,
-        batchSize: 20,
         maxRetryCount: 5,
-        retryBackoffMs: 1000,
       },
       db: getDbInstance(),
-      kafkaProducer: getKafkaProducer(),
     }),
   ],
   providers: [
@@ -61,9 +53,8 @@ export class AppModule implements NestModule, OnModuleInit {
   private readonly logger = new Logger(AppModule.name);
 
   async onModuleInit(): Promise<void> {
-    // 连接 Kafka producer（Outbox 投递前置依赖）
-    // v2.1 注：OutboxPublisher 轮询线程将被废弃（M8），由 Debezium 接管投递
-    // 此处保留 Kafka producer 连接用于其他场景（如直接发事件）
+    // 连接 Kafka producer（健康检查 /healthz 依赖 producer 探活）
+    // v2.1（M8）：OutboxPublisher 轮询线程已移除，outbox 投递由 Debezium CDC 接管
     try {
       await connectKafkaProducer();
       this.logger.log("Kafka producer connected");