[Yashwanth Reddy Verupaka (yashwanth195)]

Summary

Adds raw V8 coverage validation and compaction to support future coverage aggregation across Jest shards. Keep nested functions separate so an executed outer range does not incorrectly give coverage to an uncalled inner function.

Details

Validate every observation before merging or baseline replacement, reject incompatible source/maps and count overflow, and retain one observation per script without mutating inputs. Declare @bcoe/v8-coverage@0.2.3 directly and regenerate Rush approval and both subspaces' dependency metadata.

This does not enable sharding, collect coverage or convert reports. Callers remain responsible for JSON shape, source identity and source-map integrity checks.

How it was tested

• node common\scripts\install-run-rush.js install — passed for both subspaces.
• node common\scripts\install-run-rush.js test --only @rushstack/heft-jest-plugin --production --parallelism 4 — passed build, lint and all 42 tests after prerequisite builds.
• node common\scripts\install-run-rush.js change --verify --target-branch upstream/main --no-fetch — passed.

The 37 new cases cover real V8 nested-function capture parity, summed counts, bounded retention, both baseline orders, malformed observations, shebang/byte offsets, source/map conflicts, overflow and input isolation.

Impacted documentation

Package README only; no website documentation changes.