Soak surfaced USDCUSDT being shorted. BLUE has a hardcoded exclusion gate around
its (muted-IRP) picking: _STABLECOIN_SYMBOLS removed from prices_dict pre-select
(nautilus_event_trader.py:24/3906). Replicate exactly: VioletDecisionEngine skips
the same 10 symbols in observe() so IRP never sees them. Following BLUE in all
regards (picking unchanged; this is BLUE's separate gate). Set-equality drift
guard vs BLUE source + never-selected test. 11 tests pass.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>