[Bug]: TCGC SDK method parameter is in-consistant with operation parameters with autoRouted constant path params

[MaryGao]

Describe the bug

SDK method parameter is in-consistant with operation parameters with constant path params.

With below typespec example

@doc("show example demo")
@autoRoute
op read(@path param: "foo/bar"): void;

SDK method would have param parameter as constand type.

But relevant operation has 0 parameter. And there is no parameter in path /foo/bar.

After invetigation it is because the autoRoute feature do the replacement between the param and relevant value if it is string literal - https://github.com/microsoft/typespec/blob/main/packages/rest/src/rest.ts#L138-L143.

I think it's better to align the parameters between method and operation.

Reproduction

NA

Checklist

• Follow our Code of Conduct
• Check that this issue is about the Azure libraries for typespec. For bug in the typespec language or core libraries file it in the TypeSpec repo
• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.

[MaryGao]

I want to leverage this issue to discuss the design for method vs operation.

• it seems we have two different layers to duplicate things, why that?
• the in-consistancy would happen in parameters e.g spreading or above case
• the in-consistancy would happen in responses because of body or bodyRoot decorator
• what is the usage in getAllModels e.g op test(@bodyRoot body: {@body body: Test}): void;(how to interpret body in bodyRoot microsoft/typespec#4815)