refactor(ci): port source and test report checks to TypeScript - #768

Summary

Replace the portable-source checker and JUnit inventory comparator with typed TypeScript utilities. Compile them with the existing tsc and run the emitted JavaScript on Node 22.13.0, removing these utilities' Python dependency without relying on experimental type stripping.

Changes

• Replace two Python utilities and the source-checker test with three typed .mts files.
• Preserve source byte limits, Markdown checks, tracked-file handling, JUnit outcomes, duplicate detection, and shard matching.
• Add build:ci to emit adjacent .mjs files; generated files are ignored and excluded from the published SDK.
• Compile before running the utilities in CI, including reduced Markdown checks; update help, contributor commands, and regression tests.
• Include the sources in strict TypeScript and formatting checks. Use development dependencies for XML parsing and glob matching.

Testing

• Node 22.13.0: TypeScript compilation, canonical plugin source check, and all 9 emitted checker tests passed without experimental flags.
• Compared 26 source/XML cases against the original Python implementations: matching results.
• SDK type and formatting checks passed.
• Full SDK suites with seeds 12345 and 2474797289: each had 2,137 passes, 41 skips, and zero failures.
• Independent code review and the final committed-head review gate passed with no actionable findings.

Risk and rollout

The affected CI jobs install SDK development dependencies and compile the utilities before running them. Test fixtures compile isolated copies so parallel runs do not share generated files.

Public disclosure review

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