Add a script that takes output of dotnet-watch tests and formats it to HTML that's easier to reason about

[tmat]

Adds a vibe-coded script that helps analyzing test output of dotnet watch.

• Separates interleaving lines of output of tests running in parallel.
• Groups certain patterns of output into collapsable blocks that are collapsed by default.
• Uses different colors to distinguish various types of output (app output, watch output, test helper output).

scripts> dotnet run analyze-watch-test-output.cs https://helixr1107v0xdeko0k025g8.blob.core.windows.net/dotnet-sdk-refs-pull-53192-merge-774a9bfb9c424be389/dotnet-watch.Tests.dll.1/1/console.cbc81d8a.log?helixlogtype=result
Downloading https://helixr1107v0xdeko0k025g8.blob.core.windows.net/dotnet-sdk-refs-pull-53192-merge-774a9bfb9c424be389/dotnet-watch.Tests.dll.1/1/console.cbc81d8a.log?helixlogtype=result...
Downloaded to Temp\console.cbc81d8a.log
Wrote Temp\console.cbc81d8a.html (64 tests, 5347 input lines)

[Copilot]

Pull request overview

Adds a new utility script under scripts/ to take dotnet watch/xUnit test output logs, regroup interleaved lines by test name, and emit an HTML report with collapsible per-test sections to make failures easier to inspect.

Changes:

• Introduces parsing logic to associate xUnit log lines and result lines with individual tests and infer pass/fail/skip status.
• Generates a self-contained HTML page (CSS + JS) with filtering, expand/collapse controls, and grouped/collapsed repeated sections.

[tmat]

@DustinCampbell @MichaelSimons
Feel free to ignore the details of the script. I did :). It seems to mostly work.

[DustinCampbell]

@DustinCampbell @MichaelSimons
Feel free to ignore the details of the script. I did :). It seems to mostly work.

Successfully ignored. 😄

[tmat]

/ba-g Infra only change