[DOCS] Create API documentation for recommendation endpoints
Problem
No API documentation for recommendation service. External teams (mobile, web) keep asking for:
- Endpoint URLs
- Request/response formats
- Rate limits
- Error codes
- Authentication
Requirements
1. OpenAPI Spec (Swagger)
- Generate from FastAPI annotations
- Host at /docs endpoint
- Include examples
2. Integration Guide
- Getting started
- Authentication setup
- Code samples (Python, JS, curl)
- Common use cases
3. Architecture Docs
- How CF model works
- Caching strategy
- Performance characteristics
- Failure modes
4. Runbooks
- Deployment procedure
- Rollback procedure
- Monitoring/alerting
- Incident response
Format
- OpenAPI spec (YAML)
- Markdown docs in /docs folder
- Hosted on internal wiki
Effort
- OpenAPI: 1 day (mostly auto-generated)
- Integration guide: 2 days
- Architecture docs: 2 days
- Runbooks: 1 day
Total: 6 days