feat(http-server-csharp): add exclude-interfaces option to skip controller generation

[Copilot]

RPaaS and similar hosting platforms handle certain endpoints (e.g., ARM Operations) automatically, making the generated controller and business-logic interface files unnecessary noise.

Changes

• New emitter option exclude-interfaces (string[]) in lib.ts — lists TypeSpec interface names to skip during generation
• emitter.tsx — filters resolved interfaces against the exclusion set before passing to ControllersAndInterfaces, MockImplementations, and mock registration helpers; excluded interfaces produce no *Controller.cs or I*.cs files
• Tests — test/exclude-interfaces.test.ts covers single exclusion, multi-exclusion, no-op exclusion, and baseline (no exclusions)
• Changelog — feature entry for @typespec/http-server-csharp

Usage

# tspconfig.yaml
options:
  "@typespec/http-server-csharp":
    exclude-interfaces:
      - Operations

With the above config, OperationsController.cs and IOperations.cs are not emitted; all other interfaces are unaffected.

• Fixes [Feature request] http-server-csharp: Configuration key to turn of generating Operations controller #11494

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[abatishchev]

@copilot why it's exclude-interfaces The issue is about Operations controller. Hence the key should be called include-operations-controller of type boolean: include if true, otherwise don't. Default it to false

[Copilot]

Replaced exclude-interfaces with include-operations-controller: boolean (default false). When false (default), the controller and interface for any TypeSpec interface named exactly Operations are not generated. Set to true to include them.

Committed in the latest push.