Passport expiry warning webhook: emit event 7 days before credential expires

[leocagli]

Context

Passport #121 adds expiry notifications via webhook. This issue specifically covers the advance warning — emitting a passport.expiring_soon event 7 days before the expiry date so the agent has time to renew.

What to implement

Cron job: daily expiry scan

A scheduled job (same pattern as the existing health check cron) that runs daily and:

1. Scans all active passports
2. For each passport where expiresAt is within the next 7 days
3. Emits a passport.expiring_soon webhook event (if not already emitted for this passport in the current 7-day window — dedupe by passport ID + week)

Webhook payload

{
  "event": "passport.expiring_soon",
  "passportId": "psp_abc",
  "agentId": "bot-1",
  "expiresAt": "2026-07-03T00:00:00Z",
  "daysRemaining": 6
}

Route: GET /api/cron/expiry-warnings (cron-compatible)

Returns { checked, warned, skipped } for monitoring.

Acceptance criteria

• Passport expiring in 6 days triggers passport.expiring_soon event
• Passport expiring in 8 days does NOT trigger (outside window)
• Already-expired passport does NOT trigger (use passport.expired instead)
• Same passport not warned twice in the same 7-day window
• Unit tests: in-window, out-of-window, already-warned dedup, expired

🎁 Evidencia visual = reward extra

• Si tu PR incluye video demo o capturas de pantalla mostrando la funcionalidad pedida funcionando end-to-end, va a ser considerado para rewards de GrantFox en esta issue. No es obligatorio, pero suma mucho para la evaluación.

[AbuJulaybeeb]

hi maintainer,
i would like to take on this issue

[aliyuHabibu]

Hi, Please assign the issue to me

[grantfox-oss]

🦊 GrantFox — @AbuJulaybeeb has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #128)
2. Your PR will be reviewed by the Bitcoindefi maintainers

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