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(),
+    };
+}

SVSim.UnitTests/Config/GuildConfigDefaultsTests.cs

@@ -0,0 +1,31 @@
+using NUnit.Framework;
+using SVSim.Database.Models.Config;
+using System.Linq;
+
+namespace SVSim.UnitTests.Config;
+
+[TestFixture]
+public class GuildConfigDefaultsTests
+{
+    [Test]
+    public void ShippedDefaults_carry_capture_matching_stamps_and_caps()
+    {
+        var c = GuildConfig.ShippedDefaults();
+
+        Assert.That(c.MaxMemberNum, Is.EqualTo(30));
+        Assert.That(c.MaxSubLeaderNum, Is.EqualTo(2));
+        Assert.That(c.SearchResultCap, Is.EqualTo(50));
+        Assert.That(c.UsableStampList, Is.EqualTo(Enumerable.Range(100001, 20).ToList()));
+    }
+
+    [Test]
+    public void Property_initializers_alone_leave_stamp_list_empty()
+    {
+        // Defensive check: if someone moves UsableStampList default off ShippedDefaults
+        // and into a property initializer, the config-section tier merge will silently
+        // empty it. See feedback_config_defaults.md.
+        var c = new GuildConfig();
+        Assert.That(c.UsableStampList, Is.Empty,
+            "UsableStampList must default empty on property init; populated only by ShippedDefaults().");
+    }
+}