<objective> Audit Nyquist validation coverage for a completed phase. Three states:
- (A) VALIDATION.md exists — audit and fill gaps
- (B) No VALIDATION.md, SUMMARY.md exists — reconstruct from artifacts
- (C) Phase not executed — exit with guidance
Output: updated VALIDATION.md + generated test files. </objective>
<execution_context> @.github/thrunt-god/workflows/validate-phase.md </execution_context>
<context> Phase: $ARGUMENTS — optional, defaults to last completed phase. </context>
<process> Execute @.github/thrunt-god/workflows/validate-phase.md. Preserve all workflow gates. </process>