Add TopstepX platform support, drain withdrawal stages, and perfect-path calendar projection

- TopstepXClient (ProjectX Gateway): API-key auth, SignalR user hub,
  Trade/search daily P&L, emulated OCO exits, books-invariant
  withdrawal detection for $0-start accounts
- Platform-aware client pool, credentials (api_key column), and
  credential form; $0-size account types match by prefix alone
- Drain stages: min-day ($5-$15 randomized) MNQ legs for the
  configured days, then wait for the 50% withdrawal; stage pills
  show 'Stage N – Drain'
- Account calendar projects the perfect path: future days book their
  planned targets, simulated 50% withdrawals, payout marker

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/master-protocol.ts

@@ -128,7 +128,11 @@ export interface CatalogAccountType {
      *  firms that follow CME clearing report them (e.g. Apex: Sun/Mon/Tue around
      *  a Monday holiday is ONE trading day, recorded on the Tuesday). */
     combineCmeHolidays: boolean;
-    withdrawalStages: { profit: number; consistency: number; minTradingDays: number }[];
+    /** Per-stage config after the Nth withdrawal; the last stage repeats.
+     *  drain=true marks a spam-withdraw stage: no profit target — book
+     *  minTradingDays qualifying days of ~minDayPnL (default $5, randomized
+     *  $5–$15, traded as tiny MNQ legs), then wait for the next withdrawal. */
+    withdrawalStages: { profit: number; consistency: number; minTradingDays: number; drain?: boolean; minDayPnL?: number }[];
     /** ISO. Ties between two matching account types are broken by this. */
     updatedAt: string;
 }