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>

README.md

@@ -114,7 +114,7 @@ the batch firm's list, at random but weighted:
 
 - **Efficiency** — one contract's typical daily move ÷ one tick of spread
   (from Yahoo's hourly candles over the past week, measured once a day).
-  Commissions don't count; they're shown, never used to choose.
+  Commissions don't count — they barely differ between instruments.
 - **Session timing** — at the open every instrument gets a 10% floor and the
   weights follow efficiency; toward the last entry (14:55 CT) the floor fades
   and the weight moves sharply to the fastest movers.
@@ -126,7 +126,7 @@ the batch firm's list, at random but weighted:
   listed product (MNQ when NQ is listed).
 
 Every draw logs its odds. `GET /api/instruments` shows each firm's list with
-entry cost, daily move, hold and chance (`?simulate=10000` runs the real draw
+spread, daily move, hold and chance (`?simulate=10000` runs the real draw
 with no orders), and the master's Firms page shows the same next to each
 instrument.