CREATE TABLE multitable_outbox (
  id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
  tenant_id BIGINT UNSIGNED NOT NULL,
  audit_log_id BIGINT UNSIGNED NULL,
  resource VARCHAR(64) NOT NULL,
  resource_id BIGINT UNSIGNED NOT NULL,
  action VARCHAR(64) NOT NULL,
  payload JSON NOT NULL,
  dedupe_key VARCHAR(191) NOT NULL,
  status VARCHAR(24) NOT NULL DEFAULT 'pending',
  attempts INT NOT NULL DEFAULT 0,
  available_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
  last_error TEXT 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 (id),
  UNIQUE KEY uk_multitable_outbox_audit (audit_log_id),
  UNIQUE KEY uk_multitable_outbox_dedupe (dedupe_key),
  KEY idx_multitable_outbox_pending (status, available_at),
  KEY idx_multitable_outbox_resource (tenant_id, resource, resource_id),
  CONSTRAINT fk_multitable_outbox_tenant FOREIGN KEY (tenant_id) REFERENCES tenants(id),
  CONSTRAINT fk_multitable_outbox_audit FOREIGN KEY (audit_log_id) REFERENCES audit_logs(id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;