Report each symbol's next-leg stats to the master; drop per-symbol commission

- lib/leg-estimate: an account's next leg sized on every surveyed
  candidate (planLegSize, ranked by rankForTarget) — notional, its
  multiple of the account and the broker's maximum, expected hold, cost
  and win chance. The dashboard's hold estimate and the reporter share it.
- The reporter sends it per DXtrade firm as symbolStats, for one live
  account from the largest prefix group with a leg left to trade.
- The symbol map's per-symbol commission is gone: the firm's applies.

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

lib/master-protocol.ts

@@ -112,6 +112,36 @@ export interface FirmStats {
     /** Per account type, summing to the firm's own totals. Optional so a master
      *  on an older build simply ignores it. */
     accountTypes?: AccountTypeStats[];
+    /** DXtrade firms: one account's next leg sized on every symbol-map
+     *  candidate, best first — what the master's Firms page shows beside each
+     *  symbol. Optional. */
+    symbolStats?: SymbolStats;
+}
+
+/** How one account's next leg sizes on each candidate (see planLegSize). */
+export interface SymbolStats {
+    account: string;
+    /** The leg's dollar target, before fees and swap. */
+    leg: number;
+    targetHoldHours: number;
+    /** The leg rides without a daily-loss stop (see lastStand). */
+    lastStand: boolean;
+    /** ISO time the stats were computed. */
+    at: string;
+    symbols: {
+        symbol: string;
+        notional: number;
+        /** Notional ÷ account size. */
+        multiplier: number;
+        /** The broker's leverage on the symbol (5 = 5:1); null when unstated. */
+        maxMultiplier: number | null;
+        holdHours: number;
+        /** Expected spread, commissions and swap. */
+        cost: number;
+        winProbability: number | null;
+        volatilityPerDay: number;
+        spreadFraction: number;
+    }[];
 }
 
 export interface SchedulerState {
@@ -226,13 +256,12 @@ export function isFirmPlatform(value: unknown): value is FirmPlatform {
 }
 
 /** One symbol a DXTrade firm may trade for a CME root. Position size comes
- *  from volatility and the firm's target hold, never from the map (an older
- *  master's notionalPerContract is ignored). */
+ *  from volatility and the firm's target hold, and the commission is the
+ *  firm's (an older master's notionalPerContract or per-symbol commissionPct
+ *  is ignored). */
 export interface SymbolMapCandidate {
     /** The platform's symbol, e.g. "BTC/USD". */
     symbol: string;
-    /** Per-side commission % for this symbol; absent = the firm's. */
-    commissionPct?: number;
 }
 
 /** CME root the batch drew (NQ, MNQ, GC…) or '*' for any root not listed →