Address review findings for thread control and process discovery

- Drop the false WOW64 claim from GetContext32/SetContext32 docs and guard them for 32-bit targets only.\n- Make FrozenThread dispose the thread handles it owns; make Freeze(predicate) dispose filtered-out threads.\n- Pass the already-validated handle through GetThreadById instead of opening a second one.\n- Add no-progress guard to MemoryBase.EnumerateRegions.\n- Dispose unmatched Process candidates in ApplicationFinder.OpenProcess.\n- Clean up RemoteThreadExecutor allocation formatting.

WhiteMagic/Thread/FrozenThread.cs

@@ -7,7 +7,7 @@ namespace WhiteMagic.Thread;
 /// <summary>
 /// A disposable scope that tracks a set of threads frozen by <see cref="ThreadFactory.Freeze"/>.
 /// Disposing the scope resumes exactly those threads, in reverse order, even if the guarded
-/// body throws.
+/// body throws, and then disposes the underlying thread handles.
 /// </summary>
 public sealed class FrozenThread : IDisposable
 {
@@ -23,8 +23,7 @@ public sealed class FrozenThread : IDisposable
     public IEnumerable<RemoteThread> Threads => _threads;
 
     /// <summary>
-    /// Resumes the frozen threads in reverse order. The original call is responsible for
-    /// disposing the <see cref="RemoteThread"/> instances afterwards.
+    /// Resumes the frozen threads in reverse order, then disposes every thread handle.
     /// </summary>
     public void Dispose()
     {
@@ -41,9 +40,13 @@ public sealed class FrozenThread : IDisposable
             }
             catch
             {
-                // Resume-on-dispose is best-effort; callers keep the thread handles so
-                // they can diagnose or recover separately.
+                // Resume-on-dispose is best-effort; the handle is still disposed below.
             }
         }
+
+        foreach (RemoteThread thread in _threads)
+        {
+            thread.Dispose();
+        }
     }
 }

WhiteMagic/Thread/RemoteThread.cs

@@ -139,11 +139,17 @@ public sealed class RemoteThread : IDisposable
     }
 
     /// <summary>
-    /// Reads the 32-bit native context of the thread. Valid for 32-bit targets or
-    /// WOW64 threads selected by a 64-bit caller.
+    /// Reads the 32-bit native context of the thread. Valid only for 32-bit targets.
     /// </summary>
     public void GetContext32(out Context32 context)
     {
+        if (_memory.Is64Bit)
+        {
+            context = default;
+            throw new InvalidOperationException(
+                "Use GetContext64 for 64-bit targets; GetContext32 is valid for 32-bit targets only.");
+        }
+
         context = new Context32 { ContextFlags = ContextFlags.X86Full };
         if (!NativeMethods.GetThreadContext(_handle, ref context))
         {
@@ -153,10 +159,14 @@ public sealed class RemoteThread : IDisposable
     }
 
     /// <summary>
-    /// Writes the 32-bit native context of the thread.
+    /// Writes the 32-bit native context of the thread. Valid only for 32-bit targets.
     /// </summary>
     public void SetContext32(ref Context32 context)
     {
+        if (_memory.Is64Bit)
+            throw new InvalidOperationException(
+                "Use SetContext64 for 64-bit targets; SetContext32 is valid for 32-bit targets only.");
+
         if (!NativeMethods.SetThreadContext(_handle, ref context))
         {
             int error = Marshal.GetLastPInvokeError();

WhiteMagic/Thread/ThreadFactory.cs

@@ -86,7 +86,13 @@ public sealed class ThreadFactory
         if (threadId <= 0)
             throw new ArgumentException("Thread ID must be positive.", nameof(threadId));
 
-        SafeMemoryHandle handle = NativeMethods.OpenThread(ThreadAccess.QueryInformation, false, threadId);
+        const ThreadAccess requiredAccess =
+            ThreadAccess.SuspendResume |
+            ThreadAccess.GetContext |
+            ThreadAccess.SetContext |
+            ThreadAccess.QueryInformation;
+
+        SafeMemoryHandle handle = NativeMethods.OpenThread(requiredAccess, false, threadId);
         if (handle.IsInvalid)
         {
             int error = Marshal.GetLastPInvokeError();
@@ -115,12 +121,13 @@ public sealed class ThreadFactory
                     $"Thread {threadId} does not belong to process {_memory.ProcessId}.");
             }
 
-            // Open a handle with the rights the public RemoteThread surface needs.
-            return new RemoteThread(_memory, threadId);
+            // Ownership of the validated handle transfers to the RemoteThread.
+            return new RemoteThread(_memory, threadId, handle);
         }
-        finally
+        catch
         {
             handle.Dispose();
+            throw;
         }
     }
 
@@ -202,12 +209,39 @@ public sealed class ThreadFactory
     }
 
     /// <summary>
-    /// Suspends all threads selected by <paramref name="predicate"/>.
+    /// Suspends all target threads selected by <paramref name="predicate"/>.
     /// </summary>
     public FrozenThread Freeze(Func<RemoteThread, bool> predicate)
     {
         ArgumentNullException.ThrowIfNull(predicate);
-        return Freeze(Enumerate().Where(predicate));
+
+        var selected = new List<RemoteThread>();
+        try
+        {
+            foreach (RemoteThread thread in Enumerate())
+            {
+                try
+                {
+                    if (predicate(thread))
+                        selected.Add(thread);
+                    else
+                        thread.Dispose();
+                }
+                catch
+                {
+                    thread.Dispose();
+                    throw;
+                }
+            }
+
+            return Freeze(selected);
+        }
+        catch
+        {
+            foreach (RemoteThread thread in selected)
+                thread.Dispose();
+            throw;
+        }
     }
 
     private long GetCreationTime(int threadId)