feat: migrate IM identity and snowflake primary keys

docs/IM-群聊业务表设计.sql

@@ -3,10 +3,12 @@
 -- Database: the currently selected tenant database.
 -- Important: one tenant owns one database, so these tables intentionally do not contain tenant_id.
 -- This SQL is for review first. Do not execute directly in production before confirming indexes and migration order.
+-- Non-auto-increment BIGINT primary keys are generated by the server Snowflake generator.
 
 -- 1. Group profile and governance truth.
 -- Topic/Subscription remains the communication projection; this table is the product business truth.
 CREATE TABLE IF NOT EXISTS im_group_settings (
+  id                    BIGINT NOT NULL,
   topic                 VARCHAR(32) NOT NULL,
   owner_user_id         BIGINT NOT NULL,
   name                  VARCHAR(128) NOT NULL DEFAULT '',
@@ -27,7 +29,8 @@ CREATE TABLE IF NOT EXISTS im_group_settings (
   dissolved_at          DATETIME(3),
   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 (topic),
+  PRIMARY KEY (id),
+  UNIQUE INDEX uk_im_group_settings_topic (topic),
   INDEX idx_im_group_settings_owner (owner_user_id, group_status),
   INDEX idx_im_group_settings_status_updated (group_status, updated_at)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
@@ -135,19 +138,22 @@ CREATE TABLE IF NOT EXISTS im_group_announcements (
 
 -- 6. Announcement read receipts.
 CREATE TABLE IF NOT EXISTS im_group_announcement_reads (
+  id              BIGINT NOT NULL,
   announcement_id VARCHAR(64) NOT NULL,
   topic           VARCHAR(32) NOT NULL,
   user_id         BIGINT NOT NULL,
   read_at         DATETIME(3) NOT NULL,
   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 (announcement_id, user_id),
+  PRIMARY KEY (id),
+  UNIQUE INDEX uk_im_group_announcement_reads_announcement_user (announcement_id, user_id),
   INDEX idx_im_group_announcement_reads_topic_user (topic, user_id, read_at)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
 
 -- 7. Current member mute state.
 -- Historical changes are stored in im_group_admin_logs.
 CREATE TABLE IF NOT EXISTS im_group_mutes (
+  id          BIGINT NOT NULL,
   topic       VARCHAR(32) NOT NULL,
   user_id     BIGINT NOT NULL,
   muted_by    BIGINT NOT NULL,
@@ -160,7 +166,8 @@ CREATE TABLE IF NOT EXISTS im_group_mutes (
   version     INT NOT NULL DEFAULT 1,
   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 (topic, user_id),
+  PRIMARY KEY (id),
+  UNIQUE INDEX uk_im_group_mutes_topic_user (topic, user_id),
   INDEX idx_im_group_mutes_topic_status (topic, status, expires_at),
   INDEX idx_im_group_mutes_user_status (user_id, status, expires_at)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;