feat(guild): add GuildConfig with ShippedDefaults

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().");
+    }
+}