Allow creating users via API without invitation (service users)

What problem will this feature address?

Dokploy has a solid API for automating infrastructure and application provisioning, but currently user creation is invitation-only. This creates a hard blocker for fully automated, multi-tenant integrations (e.g. WHMCS, SaaS platforms, internal PaaS offerings).

For API-driven platforms, invitations introduce human interaction into flows that must be fully automated:

1. Cannot silently provision isolated tenants
2. Cannot create per-organization service users
3. Cannot generate per-tenant API keys programmatically
4. Forces operators to reuse a global admin API key, increasing blast radius and security risk
5. This makes Dokploy difficult to use as a backend for hosting providers and SaaS platforms.

Describe the solution you'd like

Proposed solution
Introduce API-based user creation without invitations, specifically for service / automation users.

Example
POST /api/users { "email": "service-client-123@internal", "name": "Client 123 Service User", "organization_id": "org_xxx", "role": "developer", "type": "service", "skip_invite": true }

Describe alternatives you've considered

We can't move on an build a solid integration.
No alternatives found.

Additional context

No response

Will you send a PR to implement it?

No

Start by locating the existing POST /api/users endpoint and its invitation flow. Review how organization_id, role, type, and API keys are handled, then define the service-user path so automated creation works without an invitation while preserving tenant isolation and limiting security risk.