feat(docs): service api endpoints

[kmoll]

Coolify PR: coollabsio/coolify#7338

Documentation for Service Application API Endpoints

Adds documentation for two new Service Application API endpoints that allow programmatic management of service applications.

Changes:

• New Guide: docs/knowledge-base/services-api.md - Comprehensive guide with examples, error handling, and best practices
• OpenAPI Specs: Added GET /api/v1/services/{uuid}/applications and PATCH /api/v1/services/{uuid}/applications/{app_uuid} endpoints with ServiceApplication schema
• Authorization: Updated permissions to include read and write scopes
• Navigation: Added link to new guide in Knowledge Base → Resources section
• Services Intro: Brief mention of API management capability

[github-actions]

Hi @kmoll,

The base branch of this PR has been automatically changed to next.
All contributors must commit changes to the next branch.

A maintainer will review your PR within 5 to 7 business days. Thank you!

[peaklabs-dev]

The API docs is automatically generated from the OpenAPI spec so this is not needed.