feat: Add IMsgLocalizer and improve localization support

```
Introduce IMsgLocalizer interface and improve localization functionality

- Extend `StringLocalizer` to support `IMsg` object localization and implement the new `IMsgLocalizer` interface.
- Update `.github/workflows/dotnet.yml` to use newer Actions versions, enable coverage tracking, and generate dynamic coverage badges.
- Add `IMsgLocalizer` interface and implement localization indexer in `IMsgLocalizer.cs`.
- Update dependency injection in `Startup.cs` to register `IMsgLocalizer` and refine localization services.
- Improve tests in `LocaleTest.cs` to validate `IMsgLocalizer` usage, placeholder substitution, and remove redundant assertions.

Minor: Adjust `en.yml` formatting by removing unnecessary quotes.
```

.github/workflows/dotnet.yml

@@ -28,15 +28,15 @@ jobs:
 
       - name: Build
         run: dotnet build --no-restore
-        
+
       - name: Copy Lang Folder
         run: |
           mkdir -p build_output/lang/
           cp -r TTT/Test/lang/* build_output/lang/
-        
+
       - name: Publish Test Project
         run: dotnet publish TTT/Test/Test.csproj --no-restore --no-build -o build_output -c Debug
-        
+
       - uses: actions/upload-artifact@v4
         with:
           name: build_output
@@ -61,7 +61,6 @@ jobs:
           path: build_output
 
       - name: Run tests
-#        run: "dotnet run --no-build --no-restore --project TTT/Test/Test.csproj -- --coverage --coverage-output $GITHUB_WORKSPACE/coverage.xml --coverage-output-format cobertura"
         run: "dotnet ./build_output/Test.dll --coverage --coverage-output $GITHUB_WORKSPACE/coverage.xml --coverage-output-format cobertura"
 
       - name: Code Coverage Summary Report
@@ -95,6 +94,6 @@ jobs:
           valColorRange: ${{ env.CODE_COVERAGE }}
           maxColorRange: 100
           minColorRange: 33
-          
+
       - name: Write to Job Summary
         run: cat code-coverage-results.md >> $GITHUB_STEP_SUMMARY

Locale/IMsgLocalizer.cs

@@ -0,0 +1,7 @@
+using Microsoft.Extensions.Localization;
+
+namespace TTT.Locale;
+
+public interface IMsgLocalizer : IStringLocalizer {
+  string this[IMsg msg] { get; }
+}

Locale/StringLocalizer.cs

@@ -8,7 +8,7 @@ namespace TTT.Locale;
 /// A custom implementation of <see cref="IStringLocalizer"/> that adds support
 /// for in-string placeholders like %key% and grammatical pluralization with %s%.
 /// </summary>
-public partial class StringLocalizer : IStringLocalizer {
+public partial class StringLocalizer : IStringLocalizer, IMsgLocalizer {
   public static readonly StringLocalizer Instance =
     new(new JsonLocalizerFactory());
 
@@ -112,4 +112,6 @@ public partial class StringLocalizer : IStringLocalizer {
 
     return value;
   }
+
+  public string this[IMsg msg] => localizer[msg.Key, msg.Args];
 }

TTT/Test/Locale/LocaleTest.cs

@@ -1,14 +1,21 @@
 using Microsoft.Extensions.Localization;
+using TTT.Locale;
 using Xunit;
 
 namespace TTT.Test.Locale;
 
-public class LocaleTest(IStringLocalizer localizer) {
+public class LocaleTest(IMsgLocalizer localizer) {
   [Fact]
   public void Locale_BasicTest() {
-    var msg = localizer["BASIC_TEST"];
-    
-    Assert.NotNull(msg);
-    Assert.Equal("Foobar", msg.Value);
+    var result = localizer[TestMsgs.BASIC_TEST];
+
+    Assert.Equal("Foobar", result);
+  }
+
+  [Fact]
+  public void Locale_Placeholder_Works() {
+    var msg = localizer[TestMsgs.PLACEHOLDER_TEST("Test")];
+
+    Assert.Equal("Placeholder: Test", msg);
   }
 }

TTT/Test/Startup.cs

@@ -29,7 +29,9 @@ public class Startup {
     services.AddScoped<IScheduler>(s => s.GetRequiredService<TestScheduler>());
     services.AddScoped<IGameManager, GameManager>();
     services.AddScoped<IStringLocalizerFactory, JsonLocalizerFactory>();
-    services.AddTransient<IStringLocalizer, StringLocalizer>();
+    services.AddScoped<StringLocalizer>();
+    services.AddTransient<IMsgLocalizer>(s
+      => s.GetRequiredService<StringLocalizer>());
 
     services.AddModBehavior<GenericInitTester>();
     services.AddModBehavior<PluginInitTester>();

TTT/Test/lang/en.yml

@@ -1,2 +1,2 @@
-"BASIC_TEST": "Foobar"
-"PLACEHOLDER_TEST": "Placeholder: {0}"
+BASIC_TEST: "Foobar"
+PLACEHOLDER_TEST: "Placeholder: {0}"