ICYLAB Billing Finance Read Isolation Diagnostic Fix v6.12.1

Scope:
- scripts/billing_finance_read_isolation_diagnostic_v6_12_1.php

Reason:
- Replaces the v6.12 regex method parser with token_get_all().
- Correctly recognizes methods whose signatures contain array() defaults.
- Does not modify billing services, database data, gates, or business logic.
