feat(all): add hunting and events, commerce and rewards, binary calendars, GameData caching and login diagnostics

Implement hunting AP and progress, event tasks, exchanges, games, stories and actions; connect battle and reward handling.

Add CashShop plugin and installation, server purchases and entitlements, recharge rules and plugin version metadata.

Distribute binary calendars independently; cache GameData in memory and fix single-connection query deadlocks.

Improve automatic login and recovery diagnostics; document configuration and release flows.

plugins/CashShop/CommercePayments.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+
+namespace Bd2CashShop;
+
+internal static class CommercePayments
+{
+    private static readonly HashSet<long> Applied = new HashSet<long>();
+
+    internal static string Receipt(long payment, CommerceProduct quote) =>
+        "bd2-local-commerce-v1:" + payment.ToString(CultureInfo.InvariantCulture) + ":" +
+        quote.ItemType.ToString(CultureInfo.InvariantCulture) + ":" + quote.Amount.ToString(CultureInfo.InvariantCulture);
+
+    internal static Action AcceptOnce(long payment, Func<bool> isCurrentSession, Action debit, Action continuation)
+    {
+        return delegate
+        {
+            // The transport invokes this callback only on a successful response.
+            // A replay must not charge the displayed client balance twice.
+            if (isCurrentSession() && Applied.Add(payment)) debit();
+            continuation?.Invoke();
+        };
+    }
+
+    internal static void Clear() => Applied.Clear();
+}