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/account-type-resolver.ts

@@ -12,7 +12,7 @@
  */
 
 import type { CatalogAccountType } from './master-protocol';
-import type { TradovateClient } from './tradovate-class';
+import type { PlatformClient } from './platform-client';
 import {
     getAssignment,
     setAssignment,
@@ -69,10 +69,14 @@ export function matchAccountType(
     const byPrefix = types.filter((t) => accountName.startsWith(t.prefix));
     if (byPrefix.length === 0) return { type: null, ambiguous: false };
 
-    // No size yet — stay Unassigned and try again next sync.
-    if (accountSize === null) return { type: null, ambiguous: false };
-
-    const candidates = byPrefix.filter((t) => Math.abs(t.accountSize - accountSize) < 0.01);
+    // Exact size match first. An account type with size 0 means the account's
+    // balance starts at $0 (TopstepX Express style) — there is no funding
+    // transaction to infer a size from, so it matches on prefix alone, but
+    // only once every sized candidate has had its chance.
+    const sized = accountSize !== null
+        ? byPrefix.filter((t) => t.accountSize > 0 && Math.abs(t.accountSize - accountSize) < 0.01)
+        : [];
+    const candidates = sized.length > 0 ? sized : byPrefix.filter((t) => t.accountSize === 0);
     if (candidates.length === 0) return { type: null, ambiguous: false };
     if (candidates.length === 1) return { type: candidates[0], ambiguous: false };
 
@@ -117,7 +121,7 @@ export function getAccountConfig(accountId: number): ResolvedAssignment {
 
 /** The size this account resolved to, cached once found so a later reset
  *  deposit can't move it. */
-export function getInferredSize(accountId: number, client: TradovateClient): number | null {
+export function getInferredSize(accountId: number, client: PlatformClient): number | null {
     const cached = loadAccountMeta(accountId, INFERRED_SIZE_KEY);
     if (cached !== null) {
         const value = Number(cached);
@@ -130,7 +134,7 @@ export function getInferredSize(accountId: number, client: TradovateClient): num
  *  Called after each Tradovate sync and after the catalog changes. */
 export function resolveFirmAssignments(
     firmId: string,
-    client: TradovateClient,
+    client: PlatformClient,
 ): { assigned: number; unassigned: number; manual: number } {
     const firm = getCachedFirm(firmId);
     const types = firm?.accountTypes ?? [];
@@ -184,6 +188,9 @@ export function resolveFirmAssignments(
         }
 
         if (matched.type) {
+            // A $0-start type matched on prefix alone — whatever number rode
+            // along (usually the live balance) is not an inferred size.
+            if (matched.type.accountSize === 0) matchedSize = 0;
             if (matchedSize !== null && cached === null) {
                 saveAccountMeta(account.id, INFERRED_SIZE_KEY, String(matchedSize));
             }