Refactor Kafka publishing without DB outbox

docs/sql/IM-Kafka-Outbox删除SQL.sql

@@ -0,0 +1,4 @@
+-- Remove the deprecated Kafka DB outbox table from a tenant database.
+-- Run once per tenant business database after deploying the direct Kafka publish path.
+
+DROP TABLE IF EXISTS im_kafka_outbox;

docs/sql/IM-Kafka基础表SQL.sql

@@ -29,29 +29,6 @@ CREATE TABLE IF NOT EXISTS im_kafka_consume_log (
   INDEX idx_im_kafka_consume_log_topic(source_topic, id)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
 
-CREATE TABLE IF NOT EXISTS im_kafka_outbox (
-  id BIGINT NOT NULL AUTO_INCREMENT,
-  event_id VARCHAR(96) NOT NULL,
-  topic VARCHAR(128) NOT NULL,
-  event_type VARCHAR(96) NOT NULL,
-  biz_type VARCHAR(64) NOT NULL DEFAULT '',
-  biz_id VARCHAR(128) NOT NULL DEFAULT '',
-  key_value VARCHAR(256) NOT NULL DEFAULT '',
-  envelope JSON NOT NULL,
-  status VARCHAR(16) NOT NULL DEFAULT 'pending',
-  attempts INT NOT NULL DEFAULT 0,
-  next_retry_at DATETIME(3),
-  sent_at DATETIME(3),
-  last_reason VARCHAR(64) NOT NULL DEFAULT '',
-  last_error VARCHAR(1000) NOT NULL DEFAULT '',
-  created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
-  updated_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3),
-  PRIMARY KEY(id),
-  UNIQUE INDEX uk_im_kafka_outbox_event(event_id),
-  INDEX idx_im_kafka_outbox_pending(status, next_retry_at, id),
-  INDEX idx_im_kafka_outbox_biz(biz_type, biz_id)
-) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
-
 CREATE TABLE IF NOT EXISTS im_kafka_dead_letters (
   id BIGINT NOT NULL AUTO_INCREMENT,
   dead_id VARCHAR(96) NOT NULL,