fix[backend](email): added migrations with missing email configs

[AlexSanchez-bit]

No description provided.

[github-actions]

🛑 AI review — Sensitive area, extra care recommended

This PR touches critical paths or introduces changes the model cannot judge with sufficient confidence. Review carefully before merging.

🛑 architecture (gemini-3-flash-lite) — high/critical — please review

Summary: Database migrations added, requiring Tier 3 review per architectural rules.

• high backend/migrations/000003_alert_notification_recipients.up.sql:1 — Changes to database migrations are classified as Tier 3 critical paths and require senior review and a roll-forward/backwards-compatibility plan.

✅ bugs (gemini-3-flash-lite) — clean

Summary: Database migration files for alert notification recipients look correct and safe.

No findings.

✅ security (gemini-3-flash-lite) — clean

Summary: Database migration scripts for alert notification configuration parameters added securely without introducing vulnerabilities.

No findings.

🟢 go-deps — up to date

No pending Go dependency updates.

[AlexSanchez-bit]

since the modules configs only updates prvously created entries, intrucing the new email schema needs this migration to seed those new fields