Co-authored test files flagged out-of-scope by validate_mutation_boundary despite test-alongside policy

[azalio]

Summary

validate_mutation_boundary flags test files that are co-authored with the implementation as "outside affected_files", emitting a Scope warning that blocks the first validate_step 2.4 call — on essentially every subtask. The decomposer's blueprint affected_files lists only production files, but the plan's own test policy is "tests alongside implementation (validation = pytest green)". So a test file like python/pipeline/test_<module>.py is always "unexpected".

Environment

• mapify_version: 3.10.0
• workflow: /map-efficient (batch), 25-subtask plan; test-alongside policy.

Repro

1. Implement a subtask producing python/pipeline/foo.py (in affected_files) and its test python/pipeline/test_foo.py (NOT in affected_files, but required by the test policy / HC-3 contract).
2. Run validate_step 2.4 --recommendation proceed with the changes uncommitted (working tree dirty).

Actual

{"valid": false, "message": "Scope warning (mutation-boundary): these files are outside ST-002's affected_files: ['python/pipeline/test_evidence_graph.py']. Revert the out-of-scope changes; OR, if they are genuinely required, STOP and report a blocker for a contract update — do not silently keep them. ..."}

A second validate_step 2.4 passes (once-per-subtask scope_feedback_subtasks guard, map_orchestrator.py:1184).

Root cause (hypothesis)

The decomposer (task-decomposer) emits affected_files containing only production modules, even when the subtask's validation_criteria explicitly require pytest coverage (HC-3 [AC-x] tags). validate_mutation_boundary then treats the accompanying test file as out-of-scope.

Suggested fix (one of)

1. In validate_mutation_boundary, auto-allow files matching test conventions (test_*.py, *_test.py, conftest.py, files under tests/) that sit beside a declared affected_file — they are implied by any subtask whose contract requires tests.
2. OR have the decomposer automatically add the corresponding test path(s) to each subtask's affected_files when the validation_criteria/test_strategy require tests.
3. OR add a blueprint field test_files: [] that the boundary check unions into affected_files.

Impact

A spurious "revert the out-of-scope changes / report a blocker" warning on nearly every subtask; requires a redundant second validate_step 2.4. Combined with the False-progress issue (separate report), the close path needs two validate calls regardless of whether you commit before or after validation.