/backend/monitor GET endpoint incorrectly requires body parameter (Swagger/docs and implementation do not match REST standards) #9207

Describe the bug

The /backend/monitor API endpoint currently returns an error or confusion because Swagger (OpenAPI spec) and documentation indicate that a request body is required, but the HTTP method is GET — which, by REST and OpenAPI standards, must NOT have a body. This makes the endpoint:

• Not work with standard HTTP clients and code generation tools
• Breaks Swagger UI and OpenAPI codegen
• Causes documentation and UX confusion
• Technically invalid per REST standards

File: core/http/endpoints/localai/backend_monitor.go

To Reproduce

• Visit Swagger UI or try to call /backend/monitor as GET with a body (not supported by many clients)
• See docs: backend-monitor.md shows curl -d with GET, also invalid

Expected behavior

• The model to monitor should be passed as a query parameter, not a body, e.g.: /backend/monitor?model=name
• Swagger/OpenAPI spec should mark model as a query param, not a body param
• Documentation and example cURL should reflect correct REST usage

Suggestions for the fix

1. Update Swagger annotation in [backend_monitor.go]
   • Change from:

     // @Param request body schema.BackendMonitorRequest true "Backend statistics request"

     to:

     // @Param model query string true "Model name to monitor"

2. Update handler implementation:
   • Instead of c.Bind(input), use input.Model = c.QueryParam("model") for clarity.
3. Update docs:
   • Change documentation and curl example to:

     curl "http://localhost:8080/backend/monitor?model=my-model"

4. (Optional): Consider failing with a clear error if model param is missing, and update OpenAPI/swag as well as tests.

Additional context

• This will improve REST standards conformance, client interop, and user experience.
• Note: The POST /backend/shutdown is fine as it properly uses a body per REST conventions.