Adds users.email (optional, lowercase-unique via partial index),
smtp_config singleton, and password_resets tokens. Plus the
queries U3-T2 / T3 / T4 use:
- ChangeUserPassword: self-service password change. HTTP layer
verifies the current password before this fires.
- UpdateUserProfile: set display_name + email together.
- RegenerateApiToken: invalidate old API token.
- GetUserByEmail: case-insensitive lookup for forgot-password.
- GetSMTPConfig + UpdateSMTPConfig: admin SMTP settings CRUD.
- CreatePasswordReset / GetPasswordReset / UsePasswordReset
(:execrows for atomic claim) / DeleteExpiredPasswordResets
(cron-style cleanup, not yet wired).
Email column is nullable; users without email have admin-reset
as their only password-recovery path. The lower() unique index
allows many NULLs and prevents case-insensitive duplicates.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
