Implement core diagnostic memory layer, execution helpers, and high-level facade slices

Implemented:
- Core: UTF-16 ReadString boundary/alignment fix, target bitness and process id on MemoryBase
- function interception: PatchManager, DetourManager, InstructionAnalyzer, MainThreadDispatcher
- Execution: BackgroundTaskExecutor, InProcessInvoker
- High-level: Magic facade, RemotePointer, async wrappers
- Discovery/external code loading/Window groundwork (PEB/TEB, pattern scanning, raw allocations, DLL external code loading, window/input)

Tests: 180 passing, 4 integration/interactive tests skipped.

WhiteMagicTest/Execution/InProcessInvokerTests.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Runtime.InteropServices;
+using WhiteMagic;
+using WhiteMagic.Execution;
+using Xunit;
+
+namespace WhiteMagicTest.Execution;
+
+/// <summary>
+/// Tests for <see cref="InProcessInvoker"/> operating in-process.
+/// </summary>
+public class InProcessInvokerTests
+{
+    [UnmanagedFunctionPointer(CallingConvention.Cdecl)]
+    private delegate int AddDelegate(int a, int b);
+
+    private static int NativeAdd(int a, int b) => a + b;
+
+    [Fact]
+    public void CreateFunction_calls_known_in_process_function()
+    {
+        using var reader = new InProcessReader();
+        var invoker = new InProcessInvoker(reader);
+
+        var native = new AddDelegate(NativeAdd);
+        IntPtr functionPointer = Marshal.GetFunctionPointerForDelegate(native);
+
+        AddDelegate callable = invoker.CreateFunction<AddDelegate>(functionPointer);
+        int result = callable(5, 7);
+
+        Assert.Equal(12, result);
+        GC.KeepAlive(native);
+    }
+
+    [Fact]
+    public void CreateFunction_rejects_zero_address()
+    {
+        using var reader = new InProcessReader();
+        var invoker = new InProcessInvoker(reader);
+
+        ArgumentException ex = Assert.Throws<ArgumentException>(() => invoker.CreateFunction<AddDelegate>(IntPtr.Zero));
+        Assert.Equal("address", ex.ParamName);
+    }
+
+    [Fact]
+    public void Vtable_helper_reads_function_pointer_slot()
+    {
+        using var reader = new InProcessReader();
+        var invoker = new InProcessInvoker(reader);
+
+        // Build a tiny fake vtable in a pinned buffer: two slots holding known pointers.
+        IntPtr slot0 = Marshal.GetFunctionPointerForDelegate(new AddDelegate(NativeAdd));
+        IntPtr slot1 = new IntPtr(0x12345678);
+
+        IntPtr[] vtable;
+        if (reader.Is64Bit)
+        {
+            vtable = [slot0, slot1];
+        }
+        else
+        {
+            vtable = [slot0, slot1];
+        }
+
+        GCHandle pin = GCHandle.Alloc(vtable, GCHandleType.Pinned);
+        try
+        {
+            IntPtr vTableAddress = pin.AddrOfPinnedObject();
+            Assert.Equal(slot0, invoker.ReadVTableFunction(vTableAddress, 0));
+            Assert.Equal(slot1, invoker.ReadVTableFunction(vTableAddress, 1));
+        }
+        finally
+        {
+            pin.Free();
+        }
+    }
+}