Restore a trustworthy green full lint gate for 1.0

[chubes4]

Problem

A fresh full Homeboy lint run during the WordPress.org candidate audit in #2424 found 170 PHPCS findings across 28 files on current main (164 auto-fixable, 6 manual). ESLint and PHPStan passed. The stored Homeboy lint baseline says zero, so it is stale and cannot be used as 1.0 evidence.

The package-readiness patch itself passes changed-file lint with two advisory alignment findings in SystemCommand.php; those are being corrected in #2424. The remaining whole-tree findings are pre-existing and unrelated to package metadata.

Evidence

• Full run: homeboy review --placement local lint data-machine --path /var/lib/datamachine/workspace/data-machine@audit-2424-wordpress-org-candidate
• Result: 170 PHPCS findings, ESLint 0, PHPStan 0
• 164 findings are formatter-fixable
• Six manual findings: two reserved $default parameter names, one required serialize() call requiring review/justification, one local file_get_contents() call requiring review/justification, and two callback parameters reported unused
• A homeboy refactor --from lint --write --force attempt timed out during post-fix verification without changing files

Acceptance

• Clear or narrowly justify all 170 current findings.
• Rerun the full lint gate to zero blocking findings.
• Refresh the lint baseline only from that verified run.
• Keep behavior changes separate from mechanical formatting where practical.

Refs #2424.

[chubes4]

Fresh clean-source rerun from PR #3361 now reports 168 pre-existing PHPCS findings; ESLint and PHPStan pass. The earlier 170 count included two SystemCommand alignment warnings corrected by the preparatory package PR. Full lint remains blocking and #2424 remains open.