Implement RemoteModule/RemoteFunction and prove x64 ABI at runtime

Task 7.2: export resolution + module/function facade.
- PeHeaderParser.GetExportAddress walks the PE32/PE32+ export directory and
  follows export forwarders (e.g. kernel32!HeapAlloc -> NTDLL.RtlAllocateHeap)
  into other loaded modules; ordinal and unresolvable API-set forwarders throw
  NotSupportedException.
- RemoteModule resolves a module base via Process.Modules (name match tolerant
  of .dll/case); RemoteFunction executes via RemoteThreadExecutor by default,
  exposes Address for pump routing and CreateDelegate<T> for in-process.
- Magic gains a string indexer: magic["user32"]["MessageBoxA"].

Task 3.8: add the missing live-execution ABI test - an SSE callee whose aligned
movaps #GPs unless the stub delivers a 16-byte-aligned stack, combined with a
5th stack argument. Runtime-proves shadow space, alignment, and arg placement.

Tests: 214 passing, 4 skipped.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

WhiteMagic/Magic.cs

@@ -54,6 +54,10 @@ public sealed class Magic : IDisposable
     /// <summary>Returns a <see cref="RemotePointer"/> at <paramref name="address"/>.</summary>
     public RemotePointer this[IntPtr address] => new RemotePointer(Memory, address);
 
+    /// <summary>Returns the loaded <see cref="RemoteModule"/> named <paramref name="moduleName"/>
+    /// (e.g. <c>magic["user32"]["MessageBoxA"]</c>).</summary>
+    public RemoteModule this[string moduleName] => new RemoteModule(this, moduleName);
+
     /// <inheritdoc />
     public void Dispose()
     {