Add SwarmUI settings management and portrait generation enhancements

- Introduced new API endpoints for managing SwarmUI settings, including fetching and saving presets and age rules.
- Updated the portrait generation logic to utilize the new settings structure, allowing for dynamic preset selection based on age.
- Enhanced UI components to support SwarmUI settings, including localization for new strings and improved styling for settings sections.
- Added tests to verify the functionality of new settings endpoints and portrait generation behavior.

This commit lays the groundwork for more flexible and user-friendly portrait generation options.

tests/HSchool.Server.Tests/SwarmUiSettingsStoreTests.cs

@@ -0,0 +1,43 @@
+using HSchool.Server.Game;
+
+namespace HSchool.Server.Tests;
+
+public class SwarmUiSettingsStoreTests
+{
+    [Fact]
+    public void Resolve_UsesAgeRulePreset()
+    {
+        var config = SwarmUiConfigFile.CreateDefault();
+        var profile = config.Resolve(8, PortraitKind.Avatar);
+
+        Assert.Equal("child", profile.PresetId);
+    }
+
+    [Fact]
+    public void Resolve_FallsBackToActivePresetForAdults()
+    {
+        var config = SwarmUiConfigFile.CreateDefault();
+        var profile = config.Resolve(34, PortraitKind.Full);
+
+        Assert.Equal("default", profile.PresetId);
+    }
+
+    [Fact]
+    public void NormalizeAfterLoad_MigratesLegacyFlatFile()
+    {
+        var config = new SwarmUiConfigFile
+        {
+            Model = "legacy.safetensors",
+            Steps = 12,
+            Positive = "legacy prompt",
+            Avatar = new SwarmUiKindPreset { Width = 640, Height = 640 },
+        };
+
+        config.NormalizeAfterLoad();
+
+        Assert.Single(config.Presets);
+        Assert.Equal("default", config.Presets[0].Id);
+        Assert.Equal("legacy.safetensors", config.Presets[0].Model);
+        Assert.Equal(12, config.Presets[0].Steps);
+    }
+}