Analysis: Minimum changes to move server.cs from HttpListener to Kestrel

[Copilot]

Report-only analysis of what's required to migrate server.cs from System.Net.HttpListener to Kestrel. No code changes.

Core Finding

The minimum to instantiate a RequestData after Kestrel receives a request is 3 changes:

1. New constructor on RequestData accepting HttpContext instead of HttpListenerContext
2. Change Context property type from HttpListenerContext? to HttpContext? (~30+ downstream references)
3. Property mapping in the new constructor:

public RequestData(HttpContext httpContext, string mid)
{
    Path = httpContext.Request.Path + httpContext.Request.QueryString;
    Method = httpContext.Request.Method;
    Headers = CopyToWebHeaderCollection(httpContext.Request.Headers);
    Body = httpContext.Request.Body;
    OutputStream = httpContext.Response.Body;
}

Ripple Effects

• Response API changes: .Response.OutputStream → .Response.Body, .ContentLength64 → .ContentLength, remove .Response.Close() calls
• ProxyWorker.cs: ~15 request.Context references need API updates
• AsyncWorker.cs: ~7 references for blob URI headers and status codes
• ProbeServer.cs: 3 methods change signature from HttpListenerContext → HttpContext
• EventDataBuilder.cs: 1 method signature update
• Project: SDK Microsoft.NET.Sdk.Worker → Microsoft.NET.Sdk.Web, host builder → WebApplication.CreateBuilder
• server.cs: Run() accept loop replaced by Kestrel middleware; all enqueue/validation logic unchanged

What Doesn't Change

All request processing logic (header validation, priority assignment, queue enqueue, circuit breaker checks) operates on RequestData fields — not on the HTTP context directly — and requires zero modification.

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