fix(http-server-csharp): numeric literal properties in @error models emit correct constructor parameter type

[Copilot]

@error models with numeric literal–typed properties (e.g. status: 404) generated object status = 404 in the constructor signature, which is illegal in C# (CS1763: a reference-type default may only be null). The property itself was correctly emitted as int, making the intra-class typing inconsistent.

Root cause

getExceptionConstructorData resolved constructor parameter types via getCSharpType(program, prop.type). For a Number literal, that function returns the abstract numeric scalar mapping — object — rather than the concrete numeric type.

Fix

• service.ts: When prop.type.kind === "Number", use findNumericType(prop.type) (already used by getTypeInfo for property declarations) to get the correct C# type (int or double). All other type kinds continue through getCSharpType unchanged.

Before / after

@error
model NotFoundProblem {
  title: string;
  status: 404;
}

// Before — CS1763, does not compile
public NotFoundProblem(string title, object status = 404) : base(400, ...)

// After
public NotFoundProblem(string title, int status = 404) : base(400, ...)

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• dl.google.com
  • Triggering command: /usr/lib/apt/methods/https /usr/lib/apt/methods/https (dns block)
• telemetry.astro.build
  • Triggering command: /usr/bin/node node /home/REDACTED/work/typespec/typespec/website/node_modules/.bin/../astro/bin/astro.mjs build sh k/ty�� ebsite/src/conte--llmstxt ture n-schema/node_mo../../website/src/content/docs/docs/emitters/openapi3/reference . ce n/node sh n-sc�� tspd --enable-experimental gen-extern-signature . .json .2_tmp_4732_0/node_modules/pnpm/dist/node-gyp-bin/node --no-emit iptables n-schema/referendoc node (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[timotheeguerin]

@markcowl can we wait for the csharp alloy PR to merged?