Replace count-based pass-rate with severity-weighted penalty:
- penalty = sum(count[s] * WEIGHTS[s])
- maxBudget = max(10, findingCount * 4)
- passRate = max(0, 100 - penalty / maxBudget * 100)
A few lows no longer crater an area's grade; a single high or critical
consumes a large fraction of budget. Mirrors the operator intuition that
severity, not count, is the signal.
BREAKING (intentional): scoring semantics differ from v4 for non-clean
configs. Add scoringVersion: 'v5' to the returned struct so consumers
can detect the version. baseline-all-a remains all-A (no critical/high
on that fixture).
Tests: +6 cases for severity weighting; existing "many findings" test
updated to use highs (where v5 still drops the grade as expected).
3ac313fa45