Add AGENTS.md

[dingsdax]

The repository-docs standard requires every SDK repo to have an AGENTS.md at the repository root. sentry-dotnet currently has no AGENTS.md, meaning AI agents working in this repo have no architecture context, no testing conventions, no build instructions, and no SDK-specific standard overrides. The file that makes agentic contributions accurate and consistent.

What needs to be done

1. Create AGENTS.md at the repo root. Use agents-md skill.
2. Create CLAUDE.md as a symlink: ln -s AGENTS.md CLAUDE.md
3. Fill in all SDK-specific sections:
   • Package manager and key commands (dotnet build, dotnet test, build.sh / build.cmd)
   • Architecture overview (src/ for core source, modules/ for mobile, test/, samples/, benchmarks/, integration-test/)
   • Platform targets: this warrants its own section given the mobile/non-mobile split:
     • Which solution filter to use for which area (SentryCore.slnf, SentryNoMobile.slnf, SentryMobile.slnf, SentryAspNetCore.slnf)
     • Mobile (Android/iOS) requires device tests and a platform-specific toolchain ➡️ call this out explicitly so agents don't attempt mobile builds in the wrong environment
     • Blazor WASM tests use Playwright (playwright-blazor-wasm.yml)
     • Alpine builds require separate CI (alpine.yml)
   • Development workflow (build.sh, solution filter selection, dotnet test)
   • Testing conventions (xUnit, test project naming *.Tests, integration tests in integration-test/, device tests for mobile are CI-only)
   • Standards overrides (any known deviations from the SDK standards)
4. Verify accuracy: have an AI tool attempt a small contribution using the file as context before merging

[linear]

NET-602

[jamescrosswell]

Sorry @Flash0ver - I didn't see you'd assigned this to yourself and put a draft PR together already:

• feat: Add AGENTS.md #4974

[Flash0ver]

No worries 😉 ... thanks for taking it on 🥔.