feat: backporting existing raylib-cs examples and new official raylib examples to WASM, adopting raylib's original code style

Examples/ExampleRegistry.cs

@@ -0,0 +1,53 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace Examples;
+
+/// <summary>
+/// Discovers every <see cref="IExample"/> implementation in this assembly via reflection:
+/// <see cref="DesktopExamples"/> (Program.cs) is all of them, <see cref="BrowserExamples"/>
+/// (Web/Host.cs) is everything not marked <see cref="ExcludeFromBrowserAttribute"/>.
+/// Ordering is by category (browser dropdown grouping), then display name.
+/// </summary>
+public static class ExampleRegistry
+{
+    /// <summary>Category order used for the browser dropdown and desktop run-all sequence.</summary>
+    private static readonly string[] CategoryOrder =
+    [
+        "Core",
+        "Shapes",
+        "Models",
+        "Textures",
+        "Text",
+        "Audio",
+        "Shaders",
+    ];
+
+    private static readonly IExample[] AllExamples = DiscoverAll();
+
+    public static readonly IExample[] DesktopExamples = AllExamples;
+
+    public static readonly IExample[] BrowserExamples =
+        Array.FindAll(AllExamples, e => !e.GetType().IsDefined(typeof(ExcludeFromBrowserAttribute), inherit: false));
+
+    [UnconditionalSuppressMessage("Trimming", "IL2026",
+        Justification = "The Examples assembly is rooted via TrimmerRootAssembly in Examples.csproj.")]
+    [UnconditionalSuppressMessage("Trimming", "IL2067",
+        Justification = "Same as IL2026: all example types and their parameterless constructors are rooted.")]
+    private static IExample[] DiscoverAll()
+    {
+        return typeof(IExample).Assembly
+            .GetTypes()
+            .Where(t => typeof(IExample).IsAssignableFrom(t) && t.IsClass && !t.IsAbstract)
+            .Select(t => (IExample)Activator.CreateInstance(t))
+            .OrderBy(e => Array.IndexOf(CategoryOrder, Category(e)))
+            .ThenBy(e => e.Name, StringComparer.OrdinalIgnoreCase)
+            .ToArray();
+    }
+
+    // "Examples.Core" -> "Core"
+    private static string Category(IExample example)
+    {
+        var ns = example.GetType().Namespace ?? "";
+        return ns[(ns.LastIndexOf('.') + 1)..];
+    }
+}