feat(auth): implement hybrid sync (JIT OIDC login + Webhook) for DOS.Me organizations

[JOY]

Overview

Implement Crove OS Hybrid Sync standard (JIT + Webhook) for Crove Cal (Cal.com) to synchronize Users, Profiles, and Organizations/Teams from DOS.Me ID.

Project: Crove

Subtasks

• OIDC JIT Sync:
  • Add DOS.Me OIDC provider support in NextAuth options.
  • Read sub, email, name, picture, organizations claims from OIDC userinfo.
  • Automatically create/update User and provision Team (isOrganization: true) and Membership on login.
• Webhook Event-driven Sync:
  • Implement /api/webhooks/dos-org-sync endpoint with HMAC signature verification (X-DOS-Signature: sha256=...).
  • Handle events: org.created, org.updated, org.deleted, org.member_added, org.member_removed.
  • Map organizations to Cal.com Team (isOrganization: true) and members to Membership (OWNER, ADMIN, MEMBER).
• UI Integration:
  • Add SSO Login button for DOS.Me / Crove ID.
• Verification & Testing:
  • Run type checks & verify endpoints.