test(codec): add Browser CoreCLR compatibility evidence

[SunSi12138]

Add an experimental Browser/WASM CoreCLR codec evidence graph alongside the existing .NET 10 Mono Browser lane.

The CoreCLR lane:

• pins .NET 11 RC1 SDK 11.0.100-rc.1.26425.128;
• publishes the existing Browser probe as net11.0 with UseMonoRuntime=false;
• requires the in-process identity browser-wasm-browser-coreclr-net11 / runtimeFamily=CoreCLR / wasm32;
• verifies all six desktop producer corpora, the .NET 10 Browser Mono corpus, and CoreCLR self evidence in headless Chrome;
• runs six reverse desktop consumers against the Browser CoreCLR corpus;
• retains framework raw-layout evidence without materializing unsafe incompatible raw values.

The existing Mono Browser evidence remains unchanged. Every new CoreCLR job is continue-on-error: true, so the pre-GA .NET 11 runtime evidence cannot block the existing release contract.

auto-layout-release-scoped remains evidence-only for Browser <-> desktop edges and is extended to the explicit Mono Browser <-> CoreCLR Browser cross-runtime edge. Same-runtime Browser self-roundtrip and all non-auto-layout compatibility failures remain strict.