Issue 30: Postman API Release Checklist

[laraibg786]

Goal

Finalize OpenAPI/Postman artifacts, validate all endpoints against the API, run manual testing in Postman, and publish the collection to a Postman public workspace for external partners.

Requirements

Functional

• Validate OpenAPI spec: all 15+ endpoints documented, all error codes (4xx, 5xx) included, all examples are valid JSON.
• Postman collection imports without errors; all endpoints have example requests.
• Manual test all flows: signup → login, license CRUD, activation flow, heartbeat (active/grace/expired/revoked).
• README updated with Postman import link and example curl commands.
• Publish collection to Postman public workspace with version v1.0.0.

Technical

• Artifacts: docs/openapi.json, docs/postman-collection.json, docs/postman-environment.json.
• Changelog: Document all endpoints added in this release.

Acceptance Criteria

• All 15+ endpoints pass manual testing in Postman.
• Collection published to public Postman workspace.
• README includes Postman link and curl examples.
• Changelog is complete.

Dependencies

• Blocked by: Issue 22: OpenAPI Spec and Postman Collection #22.
• Blocks: Nothing (final release artifact).