04 Plan Fingerprint v3 Audit

Verdict FINGERPRINT_V3_FAIL. Current plan hash is v2 (9bac...), while v3 is cb7f...; builder reads v2. Tests perturb synthetic composer arguments, not source data. Scope is snapshot-relative; six rows have missing inputs that collapse to 0; trigger/signals incomplete; signal v2 uses old signoff/scale. Signoff-in-fingerprint creates self-invalidating cycle.