What problem does it solve? Changes to the Mycelium plugin can silently break one host while passing on the other, and stale plugin caches make test results unreliable. This Skill provides a disciplined workflow for developing, refactoring, and reviewing the Mycelium plugin itself so cross-host changes stay correct as a system. ## Core Features & Use Cases - Cross-host TDD workflow: Reproduce defects with red regression tests, generalize the defect pattern across the branch, and implement narrow fixes that keep shared behavior host-neutral. - Regression pattern library: A references file documents 30+ known defect classes (stale plugin caches, premature mutation, lock recovery races, lineage false positives) to audit before editing. - Real-host verification: Hash-verify installed artifacts, run lifecycle audits on both Claude Code and Codex, and follow an ordered release gate before tagging versions. - Use Case: When fixing a bug in Mycelium's Stop hook, use this Skill to write a failing regression test, sweep for the same pattern in sibling modules, run the full test ladder, and verify dispatch on both hosts before release. ## Quick Start Use the develop skill to fix a bug in the Mycelium plugin's lifecycle hooks and verify it on both Claude Code and Codex.
