feat: add length guardrail sniffs

[brianvarskonst]

Summary

Adds class/file length guardrail sniffs, wires them into the standards, and raises the package runtime/CI target to PHP 8.5.

Checklist

• The change is focused and scoped to one concern.
• Tests or verification notes are included for behavior changes.
• Documentation was added or updated where needed.
• Public APIs, configuration keys, and contracts are described clearly.
• Backward compatibility impact is noted.

Type of Change

• Bug fix
• Feature
• Documentation
• Refactoring
• Maintenance
• Breaking change

Verification

• git diff --check origin/main...HEAD
• Not run locally: PHP/composer are not available in this shell; package CI should run the PHP QA commands.

Notes

Breaking change: the package now requires PHP 8.5 or newer.

[brianvarskonst]

Reviewed the package-level diff and CI result. The new length guardrails and PHP 8.5 requirement are reflected with conventional commits, including the breaking-change marker, and GitHub Actions is green. No blocking findings.