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/Windows/WindowTests.cs

@@ -0,0 +1,65 @@
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using WhiteMagic.Windows;
+using Xunit;
+
+namespace WhiteMagicTest.Windows;
+
+public sealed class WindowTests
+{
+    [Fact]
+    public void GetWindows_returns_at_least_one_top_level_window()
+    {
+        var windows = WindowFactory.GetWindows().ToList();
+        Assert.NotEmpty(windows);
+    }
+
+    [Fact]
+    public void GetWindowsByClassName_filters_to_matching_classes()
+    {
+        var all = WindowFactory.GetWindows().ToList();
+        if (all.Count == 0)
+            return;
+
+        string firstClass = all[0].ClassName;
+        if (string.IsNullOrEmpty(firstClass))
+            return;
+
+        var filtered = WindowFactory.GetWindowsByClassName(firstClass).ToList();
+        Assert.All(filtered, w => Assert.Equal(firstClass, w.ClassName));
+        Assert.True(filtered.Count <= all.Count);
+    }
+
+    [Fact]
+    public void RemoteWindow_can_query_and_manipulate_a_test_window()
+    {
+        IntPtr handle = Process.GetCurrentProcess().MainWindowHandle;
+        if (handle == IntPtr.Zero)
+        {
+            // The xUnit runner may not expose a main window; skip destructive
+            // manipulation but still validate factory enumeration above.
+            return;
+        }
+
+        var window = new RemoteWindow(handle);
+        Assert.Equal(handle, window.Handle);
+
+        string text = window.Text;
+        Assert.NotNull(text);
+
+        string originalTitle = window.Title;
+        Assert.Equal(text, originalTitle);
+
+        // Move and resize, then restore the original position.
+        bool moved = window.MoveResize(10, 10, 400, 300);
+        Assert.True(moved);
+
+        bool flashed = window.Flash();
+        Assert.True(flashed);
+
+        // Restore a sensible size without asserting exact title restoration;
+        // terminal windows often ignore SetWindowText.
+        bool restored = window.MoveResize(0, 0, 800, 600);
+        Assert.True(restored);
+    }
+}