[codex] Validate make and just command references

[baskduf]

Summary

• Validate root make targets and root just recipes cited by failure-memory records, adoption reports, and task outcome verification evidence.
• Keep root scripts and generic template copies in sync.
• Update ADR/roadmap language and add task outcome evidence for the substantial harness-maintenance work.

Why

This closes a fake-command evidence gap: harness records could previously cite make check or just verify as concrete checks even when the target repository did not define those commands.

Validation

• python3 -m unittest discover -s tests (146 tests, 1 skipped)
• python3 -m py_compile scripts/apply_harness.py scripts/check_docs_drift.py scripts/check_structure.py scripts/check_encoding_hygiene.py scripts/check_effectiveness_plan.py scripts/check_failure_memory.py scripts/check_decision_memory.py scripts/harness_doctor.py
• python3 scripts/check_docs_drift.py
• python3 scripts/check_structure.py
• python3 scripts/check_encoding_hygiene.py
• python3 scripts/check_effectiveness_plan.py
• python3 scripts/check_failure_memory.py
• python3 scripts/check_decision_memory.py
• python3 scripts/harness_doctor.py --target . (98/100)
• git diff --check

Review Notes

• Primary-agent review fixed a test assertion indentation issue and a make inline-code delimiter miss.
• Read-only subagent review found issues around task-outcome false-inclusion validation, GNU Makefile precedence, make variable assignments, and just default-parameter parsing; those were fixed and re-reviewed.
• Final subagent result: No actionable findings remain.

Remaining Scope

This intentionally covers root Makefile/justfile variants. make -C ..., included makefiles, Maven, Gradle, Go, and other task runners remain future roadmap scope.