conditional-preservation-checklisted

# Conditional Preservation Check ## Purpose On fold/merge/rename operations, detect silently dropped conditional branches or guard clauses. A refactor that consolidates two similar-looking code paths can easily lose a branch that only one of them handled — this skill exists to catch that specific failure mode before it ships as a silent behavior regression. This is a power skill, not a lifecycle phase. It is active: invoked by Build when a refactor's diff shape indicates a fold/merge/rename operation touching control flow, not a fixed gate every Build phase runs through. ## Invocation Context Use this skill when: - the diff removes a function, branch, or file whose logic is absorbed into another location (a fold or merge) - the diff renames a function/module in a way that also restructures its internal control flow, not just its identifier - the task description itself names a refactor, consolidation, or deduplication as its purpose Do not invoke it for a diff that only adds new code with no removed/restructured control flow, or for a pure rename with no logic change (identifier-only, structure untouched). ## What To Load **Foundation** (confirm in context; load if not already present): - Root `AGENTS.md` - `workflow/router.md` - `workflow/lifecycle.md` - `workflow/rules.md` **Minimum for invocation**: - This file - `references/output-schema.md` **Before starting work**: - `references/detection-method.md` — how to compare pre- and post-refactor control flow for dro