Add Terraform provider and CLI automation

[jusso-dev]

Problem

Infrastructure teams should be able to manage monitors, status pages, and notification channels as code.

Scope

• Stabilize API schemas needed for automation.
• Add a Go CLI for monitor CRUD, check-now, incident list, status-page sync, import, and export.
• Create a Terraform provider for monitors, notification channels, maintenance windows, and status page components.
• Add examples for CI usage.

Acceptance criteria

• CLI can authenticate with API key and perform core CRUD operations.
• Terraform provider can create/update/delete core monitoring resources idempotently.
• Acceptance tests can run against a local Docker Compose stack.
• Docs include import/export examples.
• API compatibility expectations are documented.

Notes

This issue is part of the GoUpTime product roadmap.