test(paseo-omp): cover OMP cancellation outcomes

[omercnet]

Summary

• add observable provider regressions: native abort with error text produces exactly one canceled turn, genuine native failure remains failed, and later turns complete
• record #5101, #4921, and merged #5243 (90737e1) in the existing core-provider audit row
• document that detached-child Stop behavior remains intentionally unchanged pending product direction in Should foreground Stop preserve detached OMP child sessions? getpaseo/paseo#5256

Deliberate non-change

Parent cancellation continues to terminalize all subsessions. Preserving only detached child descriptors is unsafe while shared host-tool cleanup can abort the child’s in-flight work.

Verification

• npm test -- tests/provider-interrupt.test.ts — 17 passed
• npm run typecheck
• npm run check

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.