git:20260907.d6830fe to git:20261009.e2bf3c3

6 added, 0 removed. Audit A to A.

# infrastructure/core/testing — agent contract

Test-execution machinery for the template: the per-project pytest runner,

profiles/markers, receipts, coverage probes, and the advisory test-impact

planner. Re-homed from the flat `infrastructure/core/` top level by

`CORE-TESTING-REHOME-1`.

## Invariants

1. `infrastructure/core/<module>.py` shims re-export this package's surface;

old import paths must keep resolving (import parity is the re-home

contract). New code imports `infrastructure.core.testing.<module>`.

2. Private names are package-internal. The shims re-export only the five

externally-consumed privates (`_output_tree_digest`, `_contains_tests`,

`_cache_identity_inputs`, `_resolve_roster_revision`,

`_redact_output_tail`); everything else imports from the new path.

3. General core utilities (`determinism.py`, `script_discovery.py`,

`runtime/`, `logging/`, …) stay at the core top level — membership here

means "test-execution machinery", not "used by tests".

## Public surface

See `README.md` for the module table. Key entry points:

`run_per_project_pytest`, `build_union_pytest_command`, `resolve_test_profile`,

`write_public_matrix_receipt`, `run_project_test_matrix`, `output_tree_digest`,

`declared_output_relpaths`, `classify_changed_paths`, `check_cov_datafile_support`.

## Cross-refs

- `infrastructure/core/AGENTS.md` — the parent core contract.

- `tests/infra_tests/core/` — the suite exercising this package.

- Root `TO-DO.md` row `CORE-TESTING-REHOME-1` (closed by this re-home).

+ ## Release acceptance modules

+ | Module | Role |

+ | --- | --- |

+ | `project_test_runtime.py` | Admission of an already prepared project test interpreter; never a resolver. |