Move CertInfo struct from provider.go to internal/autocert/types/cert_info.go and
replace global ActiveProvider.Load() with context-based autocertctx.FromCtx() pattern in API handlers.
This improves separation of concerns and eliminates global state dependency in request handling.
- Introduced a new method `GetCertInfos` to fetch details of all available certificates.
- Updated the `Info` handler to return an array of `CertInfo` instead of a single certificate.
- Improved error handling for cases with no available certificates.
- Refactored related error messages for clarity.
- These changes makes the API incombatible with previous versions
- Added new types for error handling, success responses, and health checks.
- Updated health check logic to utilize the new types for better clarity and structure.
- Refactored existing handlers to improve response consistency and error handling.
- Updated Makefile to include a new target for generating API types from Swagger.
- Updated "new agent" API to respond an encrypted cert pair
