docs: add WooCommerce compatibility audit

[anyelopetit]

Summary

• documents the verified local maintenance flow for install, tests, format check, and production build
• adds a WooCommerce hook/API audit with HPOS assessment and deferred compatibility declaration guidance
• adds a compatibility matrix for PHP, WordPress, WooCommerce, stubs, and release packaging
• expands release checklist and packaging verification notes
• records Dependabot triage outcomes for the open dependency-only PRs

Verification

• composer format:check

Notes

• no runtime plugin behavior changes
• HPOS declaration is intentionally documented but not added until manual runtime smoke testing passes with HPOS enabled and disabled