feat(guild): add GuildConfig with ShippedDefaults

SVSim.Database/Models/Config/GuildConfig.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace SVSim.Database.Models.Config;
+
+/// <summary>
+/// Guild-feature configuration: membership caps, search caps, stamp palette,
+/// and chat-polling intervals. All collection defaults live in
+/// <see cref="ShippedDefaults"/> (not property initializers) to survive the
+/// GameConfigService tier-merge correctly.
+/// </summary>
+[ConfigSection("Guild")]
+public sealed class GuildConfig
+{
+    public int MaxMemberNum { get; init; } = 30;
+    public int MaxSubLeaderNum { get; init; } = 2;
+    public int SearchResultCap { get; init; } = 50;
+    public int ChatPollIdleSeconds { get; init; } = 10;
+    public int ChatPollActiveSeconds { get; init; } = 3;
+    public List<int> UsableStampList { get; init; } = new();
+
+    public static GuildConfig ShippedDefaults() => new()
+    {
+        UsableStampList = Enumerable.Range(100001, 20).ToList(),
+    };
+}