Write job artifact files atomically

[chubes4]

Summary

• Write job artifact JSON through same-directory temp files with locked writes and atomic rename to avoid partial final files during concurrent workers or interrupted writes.
• Keep artifact paths stable and repeat writes idempotent while cleaning up temp files on failure.
• Extend the hashable artifact smoke coverage for stale final-file replacement, repeated byte-identical writes, and temp-file cleanup.

Issues

• Starts Write job artifact files atomically and idempotently #2415
• Leaves Add atomic engine_data update primitives for concurrent workers #2413 and Harden batch fan-out for large payloads and duplicate delivery #2414 for follow-up PRs.

Tests

• php tests/job-artifact-hashable-smoke.php
• php -l inc/Core/JobArtifacts.php && php -l tests/job-artifact-hashable-smoke.php
• ./vendor/bin/phpcs inc/Core/JobArtifacts.php tests/job-artifact-hashable-smoke.php
• homeboy test --path "/Users/chubes/Developer/data-machine@harden-runtime-state-atomic-artifacts" --extension wordpress (1305 passed, 3 skipped)

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (GPT-5.5)
• Used for: Drafted the focused atomic artifact write implementation and targeted smoke coverage; Chris remains responsible for review and merge.

[homeboy-ci]

Homeboy Results — data-machine

Lint

❌ lint — failed

Deep dive: homeboy lint data-machine --changed-since 424a39a

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-lint-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-lint-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26714770888

Test

✅ test — passed

ℹ️ Auto-fix lint issues: homeboy refactor data-machine --from lint --write
ℹ️ Collect coverage: homeboy test data-machine --coverage
ℹ️ Pass args to test runner: homeboy test -- [args]
ℹ️ Full options: homeboy docs commands/test
Deep dive: homeboy test data-machine --changed-since 424a39a

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-test-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-test-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26714770888

Audit

✅ audit — passed

• audit — 3 finding(s)
• Total: 3 finding(s)

Deep dive: homeboy audit data-machine --changed-since 424a39a

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-data-machine-audit-quality-Linux-node24 contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-data-machine-audit-quality-Linux-node24 contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/data-machine/actions/runs/26714770888

Tooling versions

• Homeboy CLI: homeboy 0.213.4+bcc6d098
• Extension: wordpress from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: 06cc67ae
• Action: unknown@unknown