Fix FIFO verifier masking in corpus scores

[luisleo526]

Summary

• require a real cross-entry, multi-exit FIFO collision before using schedule-level rescue
• evaluate eligibility only on exact scored raw entry groups, including shifted matched counterparts without importing out-of-gate rows
• penalize surplus engine quantity on shared exit events symmetrically
• add nine focused regression tests and register them with CTest

Why

The old duplicate-entry guard also matched ordinary margin-call fragments and could replace per-trade PnL error with whole-window net PnL. In the downstream 402-strategy board this falsely inflated two tiers: z8830 Excellent to Strong after correction, and Van VWAP Strong to Moderate. The corrected board is 346 Excellent / 47 Strong / 4 Moderate / 5 Weak. The public engine corpus remains 246 Excellent / 5 Strong / 1 Anomaly.

Validation

• focused verifier tests: 9/9
• CTest: 111/111
• full run_corpus.sh: 252/252 strategies; 246 Excellent / 5 Strong / 1 Anomaly
• verifier self-test: 4/4
• validation report self-test: 252/252
• two independent cold reviews: PASS