-- Profile-jump identities are intentionally separate from legacy HMAC identities.
-- No username-based backfill. Existing-account binding requires reviewed explicit IDs.
CREATE TABLE IF NOT EXISTS platform_external_identity (
 id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
 issuer VARCHAR(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
 tenant_id VARCHAR(96) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
 external_user_id VARCHAR(96) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
 user_id BIGINT UNSIGNED NOT NULL,
 created_at DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
 UNIQUE KEY uq_external_identity (issuer,tenant_id,external_user_id),
 UNIQUE KEY uq_external_platform_user (user_id),
 CONSTRAINT fk_external_identity_user FOREIGN KEY(user_id) REFERENCES platform_user(id) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;