-- AlterTable: Add clerk_id column and remove password_hash
ALTER TABLE `users` ADD COLUMN `clerk_id` VARCHAR(255) NULL;

-- Create unique index on clerk_id
CREATE UNIQUE INDEX `clerk_id` ON `users`(`clerk_id`);

-- Create index for clerk_id lookups
CREATE INDEX `idx_clerk_id` ON `users`(`clerk_id`);

-- Drop password_hash column (after data migration if needed)
-- Note: In production, you would first migrate existing users to Clerk before dropping this column
-- For now, we'll keep it to avoid data loss, but it should be removed after Clerk migration is complete
-- ALTER TABLE `users` DROP COLUMN `password_hash`;