Preserve field availability before normalization

When an optional provider field controls verification, preserve whether it was missing, malformed, explicitly empty, or populated before normalization. Collapsing all states to null can erase an expectation and skip a mismatch. If a decision requires refresh, propagate refresh failure through outer fallback handlers so stale data cannot settle it. Scope fail-closed behavior to decision-relevant fields and test omission, null, blank, aliases, persistence, errors, and retries.