fix shared-db tenant runtime gaps

docs/IM-数据库变更汇总.sql

@@ -166,6 +166,7 @@ CREATE TABLE IF NOT EXISTS tinode.im_system_notifications (
 
 CREATE TABLE IF NOT EXISTS tinode.im_http_idempotency (
   id              BIGINT NOT NULL AUTO_INCREMENT,
+  tenant_id       BIGINT NOT NULL DEFAULT 0,
   user_id         BIGINT NOT NULL,
   method          VARCHAR(8) NOT NULL,
   route           VARCHAR(512) NOT NULL,
@@ -178,7 +179,7 @@ CREATE TABLE IF NOT EXISTS tinode.im_http_idempotency (
   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_http_idempotency_scope (user_id, method, route, idempotency_key),
+  UNIQUE INDEX uk_im_http_idempotency_scope (tenant_id, user_id, method, route, idempotency_key),
   INDEX idx_im_http_idempotency_expiry (expires_at)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;