copilot-instructions.md documents `dotnet test` for server tests, which fails on .NET 10

Problem

.github/copilot-instructions.md line 60 says:

• Run server tests: dotnet test from the ServerTests project.

That command no longer works. Running it in src/ServerTests fails before any test executes:

error : Testing with VSTest target is no longer supported by Microsoft.Testing.Platform
on .NET 10 SDK and later. If you use dotnet test, you should opt-in to the new dotnet test
experience. For more information, see https://aka.ms/dotnet-test-mtp-error
[src/ServerTests/ServerTests.csproj]

The project uses Microsoft.Testing.Platform, and under the .NET 10 SDK the VSTest target it routes through is gone.

What actually works

cd src/ServerTests
dotnet run

Test run summary: Passed! - src/ServerTests/bin/Debug/net10.0/ServerTests.dll (net10.0|x64)
  total: 214
  failed: 0
  succeeded: 214
  skipped: 0

Why this is worth fixing

The instructions file is the first thing an AI agent reads before touching this repo, and it is the documented entry point for contributors. A command that fails immediately sends the reader down a dead end at exactly the moment they are trying to verify their work.

The failure is also easy to misread. It surfaces as a red error : from an MSBuild target with a non-zero exit code, so it looks like a broken build or a failing test suite rather than a wrong command — the plausible next move is to start "fixing" code that was never broken.

This happened during a real session: the documented command was run against a green branch, failed, and needed a second attempt with dotnet run to discover all 214 tests actually pass.

Note CI is unaffected — the Unit Tests (Server/.NET) job passes, so it is invoking the suite some other way. Only the documented local command is wrong.

Suggested fix

Update line 60 to dotnet run, and ideally align it with however the CI job invokes the tests so the documented command and CI stay in agreement.

Worth checking whether ARCHITECTURE.md or the README repeat the same dotnet test instruction.

Start in .github/copilot-instructions.md around line 60 and verify the documented server-test command from src/ServerTests. Check whether ARCHITECTURE.md or the README repeat the same instruction, and compare with the CI job’s test invocation. Done means contributor-facing instructions use a working command and no conflicting local guidance remains.