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/core-edu/src/main.ts

@@ -3,7 +3,6 @@ import { AppModule } from "./app.module.js";
 import { env } from "./config/env.js";
 import { connectKafka, disconnectKafka } from "./config/kafka.js";
 import { connectRedis, disconnectRedis } from "./config/redis.js";
-import { outboxPublisher } from "./shared/outbox/outbox.publisher.js";
 import { GlobalErrorFilter } from "./shared/errors/global-error.filter.js";
 import { initTracer, shutdownTracer } from "./shared/observability/tracer.js";
 import { logger } from "./shared/observability/logger.js";
@@ -24,9 +23,9 @@ async function bootstrap(): Promise<void> {
     res.end(await registry.metrics());
   });
 
-  // Connect Kafka producer/consumer before starting the outbox publisher.
-  // Non-blocking: if Kafka is unavailable, service still starts; outbox
-  // publisher will retry sends and messages stay pending until Kafka recovers.
+  // Connect Kafka producer/consumer.
+  // Non-blocking: if Kafka is unavailable, service still starts.
+  // v2.1（M8）：OutboxPublisher 轮询线程已移除，outbox 投递由 Debezium CDC 接管。
   void connectKafka();
 
   // Connect Redis for distributed lock (homework submission idempotency).
@@ -34,10 +33,6 @@ async function bootstrap(): Promise<void> {
   // operations will fall back to DB unique index for idempotency.
   void connectRedis();
 
-  // Start the transactional outbox publisher - polls pending messages
-  // and publishes them to Kafka topics defined in TOPIC_MAP.
-  await outboxPublisher.start();
-
   await app.listen(env.PORT);
 
   // 启动 gRPC server（9 Service / 40 RPC）
@@ -51,7 +46,6 @@ async function bootstrap(): Promise<void> {
   const shutdown = async (signal: string): Promise<void> => {
     logger.info({ signal }, "Shutting down gracefully...");
     await stopGrpcServer();
-    await outboxPublisher.stop();
     await disconnectRedis();
     await disconnectKafka();
     await shutdownTracer();

services/core-edu/src/shared/lifecycle/lifecycle.service.ts

@@ -7,7 +7,6 @@ import {
 import { closeDb } from "../../config/database.js";
 import { disconnectRedis } from "../../config/redis.js";
 import { disconnectKafka } from "../../config/kafka.js";
-import { outboxPublisher } from "../outbox/outbox.publisher.js";
 
 const SERVICE_NAME = "core-edu";
 
@@ -24,7 +23,6 @@ export class LifecycleService implements OnModuleInit, OnApplicationShutdown {
       `service ${SERVICE_NAME} shutting down (signal=${signal ?? "unknown"})`,
     );
     try {
-      await outboxPublisher.stop();
       await disconnectRedis();
       await disconnectKafka();
       await closeDb();

services/core-edu/src/shared/outbox/outbox.publisher.ts

@@ -1,119 +0,0 @@
-import { logger } from "../observability/logger.js";
-import { producer } from "../../config/kafka.js";
-import { outboxRepository } from "./outbox.repository.js";
-import type { OutboxMessage } from "./outbox.schema.js";
-
-/**
- * TOPIC_MAP: 事件类型 → Kafka topic
- *
- * 仲裁依据：ISSUE-002 / ISSUE-004 / events.proto 头注释
- * 命名规范：edu.teaching.<aggregate>.<action>
- */
-const TOPIC_MAP: Record<string, string> = {
-  // Exam events
-  "exam.created": "edu.teaching.exam.created",
-  "exam.updated": "edu.teaching.exam.updated",
-  "exam.published": "edu.teaching.exam.published",
-  "exam.submitted": "edu.teaching.exam.submitted",
-  "exam.graded": "edu.teaching.exam.graded",
-  "exam.deleted": "edu.teaching.exam.deleted",
-  // Exam realtime events (P3.14: 供 msg → push-gateway → student-portal WebSocket)
-  "exam.extended": "edu.teaching.exam.extended",
-  "exam.force_submitted": "edu.teaching.exam.force_submitted",
-  "exam.question_reordered": "edu.teaching.exam.question_reordered",
-  // Homework events
-  "homework.assigned": "edu.teaching.homework.assigned",
-  "homework.submitted": "edu.teaching.homework.submitted",
-  "homework.graded": "edu.teaching.homework.graded",
-  // Grade events
-  "grade.recorded": "edu.teaching.grade.recorded",
-  "grade.updated": "edu.teaching.grade.updated",
-  // Attendance events
-  "attendance.recorded": "edu.teaching.attendance.recorded",
-  // Class events (ISSUE-004: 统一为 edu.teaching.class.transferred)
-  "class.transferred": "edu.teaching.class.transferred",
-};
-
-const POLL_INTERVAL_MS = 5000;
-const BATCH_SIZE = 100;
-const MAX_RETRY = 5;
-const RETRY_BACKOFF_BASE_MS = 1000;
-
-export class OutboxPublisher {
-  private intervalId: NodeJS.Timeout | null = null;
-  private isPolling = false;
-
-  async start(): Promise<void> {
-    logger.info("OutboxPublisher started");
-    this.intervalId = setInterval(() => {
-      void this.poll();
-    }, POLL_INTERVAL_MS);
-  }
-
-  async stop(): Promise<void> {
-    if (this.intervalId) {
-      clearInterval(this.intervalId);
-      this.intervalId = null;
-    }
-    logger.info("OutboxPublisher stopped");
-  }
-
-  private async poll(): Promise<void> {
-    if (this.isPolling) return;
-    this.isPolling = true;
-    try {
-      const messages = await outboxRepository.findPending(BATCH_SIZE);
-      for (const message of messages) {
-        await this.publish(message);
-      }
-    } catch (error) {
-      logger.error({ error }, "Outbox poll failed");
-    } finally {
-      this.isPolling = false;
-    }
-  }
-
-  private async publish(message: OutboxMessage): Promise<void> {
-    const topic = TOPIC_MAP[message.eventType] ?? "edu.teaching.fallback";
-    try {
-      await producer.send({
-        topic,
-        messages: [
-          {
-            key: message.aggregateId,
-            value: message.payload,
-            headers: {
-              eventType: message.eventType,
-              aggregateType: message.aggregateType,
-              eventId: message.eventId,
-            },
-          },
-        ],
-      });
-      await outboxRepository.markProcessed(message.id);
-      logger.info(
-        {
-          id: message.id,
-          eventId: message.eventId,
-          eventType: message.eventType,
-          topic,
-        },
-        "Outbox message published",
-      );
-    } catch (error) {
-      logger.error(
-        { error, id: message.id, eventId: message.eventId },
-        "Outbox publish failed",
-      );
-      const nextRetry = message.retryCount + 1;
-      if (nextRetry >= MAX_RETRY) {
-        await outboxRepository.markFailed(message.id);
-      } else {
-        const backoff = RETRY_BACKOFF_BASE_MS * Math.pow(2, nextRetry);
-        await outboxRepository.incrementRetry(message.id, backoff);
-      }
-    }
-  }
-}
-
-export const outboxPublisher = new OutboxPublisher();