plan(lvl5): N/A split — intentional skip climbs, unintentional (unverified) blocks

Operator refinement: only declared/structural skips (not backup-capable, no
previous version) let the climb continue; a rung that should have run but
didn't (infra error, abra missing, tier abort, timeout) blocks the level at
the last verified rung. Every N/A source in derive_rungs gets an explicit
classification (DECISIONS.md, adversary-reviewed); unclassifiable defaults to
unverified. Unit tests + one synthesized tier-abort run prove the rule.

cc-ci-plan/JOURNAL.md

@@ -416,3 +416,9 @@ session cc-ci-orchestrator-stale can be killed; recipe-mirrors org still private
 - Deliberate override of Phase-3 "N/A caps" stance — to be recorded in DECISIONS.md by
   the loops. Before/after level table for all recipes required so the Adversary can
   attribute every level shift to the rule change.
+
+## 2026-06-11 ~02:00 — lvl5 refinement: intentional vs unintentional N/A
+- Operator: an N/A rung only skips if it's an INTENTIONAL skip (declared/structural:
+  not backup-capable, no upgrade target). UNINTENTIONAL N/A (infra error, missing tool,
+  aborted tier = unverified) blocks — the level cannot be above an unverified rung.
+  Statuses now {pass, fail, skip, unver}; unclassifiable N/A defaults to unver.