fix(cli): validate migration name and correctly report created migration files #4103

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Final Result: Bugbot completed review and found 1 potential issue.

Request ID: serverGenReqId_d6892a6c-b586-4557-99db-c1f4afc14178

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Reviewed by Cursor Bugbot for commit 7fa0b52. Configure here.}