Initial commit: LegacyForge mod loader for Minecraft Legacy Edition

SKSE-style external mod loader with zero game source modifications.
- LegacyForge.Launcher: C# console app that injects runtime DLL into game process
- LegacyForgeRuntime: C++ DLL with PDB symbol resolution, MinHook function hooking, and .NET CoreCLR hosting
- LegacyForge.Core: C# mod discovery and lifecycle management
- LegacyForge.API: Fabric-style mod API with namespaced string IDs, fluent property builders, and event system
- ExampleMod: Sample mod demonstrating block/item registration

ExampleMod/ExampleMod.cs

@@ -0,0 +1,52 @@
+using LegacyForge.API;
+using LegacyForge.API.Block;
+using LegacyForge.API.Item;
+using LegacyForge.API.Events;
+
+namespace ExampleMod;
+
+[Mod("examplemod", Name = "Example Mod", Version = "1.0.0", Author = "LegacyForge",
+     Description = "A sample mod demonstrating the LegacyForge API")]
+public class ExampleMod : IMod
+{
+    public static RegisteredBlock? RubyOre;
+    public static RegisteredItem? Ruby;
+
+    public void OnInitialize()
+    {
+        RubyOre = Registry.Block.Register("examplemod:ruby_ore",
+            new BlockProperties()
+                .Material(MaterialType.Stone)
+                .Hardness(3.0f)
+                .Resistance(15f)
+                .Sound(SoundType.Stone)
+                .Icon("ruby_ore"));
+
+        Ruby = Registry.Item.Register("examplemod:ruby",
+            new ItemProperties().MaxStackSize(64));
+
+        Registry.Recipe.AddFurnace("examplemod:ruby_ore", "examplemod:ruby", 1.0f);
+
+        GameEvents.OnBlockBreak += OnBlockBroken;
+
+        Logger.Info("Example Mod initialized! Ruby ore and ruby registered.");
+    }
+
+    private void OnBlockBroken(object? sender, BlockBreakEventArgs e)
+    {
+        if (RubyOre != null && e.BlockId == RubyOre.StringId.ToString())
+        {
+            Logger.Info($"Ruby ore broken at ({e.X}, {e.Y}, {e.Z})!");
+        }
+    }
+
+    public void OnTick()
+    {
+        // Per-tick logic goes here
+    }
+
+    public void OnShutdown()
+    {
+        Logger.Info("Example Mod shutting down.");
+    }
+}