Instruments: no fee lookup — commissions barely differ between instruments

Entry cost is one tick of spread; fees can be added later if they matter.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/master-protocol.ts

@@ -138,8 +138,6 @@ export interface InstrumentStats {
         contract: string | null;
         /** One tick of spread on one contract, in dollars. */
         spreadDollars: number;
-        /** The firm's fees per contract per side; null when unknown. */
-        feesPerSide: number | null;
         /** One contract's typical daily move (1σ), in dollars. */
         dailyMoveDollars: number | null;
         holdHours: number | null;