fix(compat): keep Runtime helpers compiling when Physics 2D / Screen Capture modules are disabled (#1160)

v9.7.0 introduced two Runtime regressions that block compilation when users
disable the matching built-in modules in Package Manager:

- UnityPhysicsCompat.cs used `typeof(Physics2D)` directly, contradicting the
  file's own contract of reflection-based access ("survive eventual removal
  without recompile"). Switched to `Type.GetType("UnityEngine.Physics2D,
  UnityEngine.Physics2DModule")` so the shim degrades gracefully when the
  Physics 2D module is off.

- ScreenshotUtility.CaptureComposited bypassed the existing reflective
  ScreenCapture path (s_captureScreenshotMethod) with a direct call to
  ScreenCapture.CaptureScreenshotAsTexture. Cached a second MethodInfo
  (s_captureScreenshotAsTextureMethod) and routed the call through it, so
  the file compiles with the Screen Capture module disabled and falls back
  to camera capture at runtime — matching the behavior the file already
  advertises via IsScreenCaptureModuleAvailable.

Author: Scriptwonder

MCPForUnity/Runtime/Helpers/ScreenshotUtility.cs

@@ -53,6 +53,7 @@ public static class ScreenshotUtility
         private static bool s_loggedLegacyScreenCaptureFallback;
         private static bool? s_screenCaptureModuleAvailable;
         private static System.Reflection.MethodInfo s_captureScreenshotMethod;
+        private static System.Reflection.MethodInfo s_captureScreenshotAsTextureMethod;
 
         /// <summary>
         /// Checks if the Screen Capture module (com.unity.modules.screencapture) is enabled.
@@ -72,6 +73,8 @@ public static bool IsScreenCaptureModuleAvailable
                     {
                         s_captureScreenshotMethod = screenCaptureType.GetMethod("CaptureScreenshot",
                             new Type[] { typeof(string), typeof(int) });
+                        s_captureScreenshotAsTextureMethod = screenCaptureType.GetMethod("CaptureScreenshotAsTexture",
+                            new Type[] { typeof(int) });
                     }
                 }
                 return s_screenCaptureModuleAvailable.Value;
@@ -249,7 +252,7 @@ public static ScreenshotCaptureResult CaptureComposited(
             int maxResolution = 0,
             string folderOverride = null)
         {
-            if (!IsScreenCaptureModuleAvailable)
+            if (!IsScreenCaptureModuleAvailable || s_captureScreenshotAsTextureMethod == null)
             {
                 var fallbackCamera = FindAvailableCamera();
                 if (fallbackCamera != null)
@@ -266,7 +269,9 @@ public static ScreenshotCaptureResult CaptureComposited(
             int imgW = 0, imgH = 0;
             try
             {
-                tex = ScreenCapture.CaptureScreenshotAsTexture(result.SuperSize);
+                // Reflective call to ScreenCapture.CaptureScreenshotAsTexture so the file compiles
+                // even when the Screen Capture module (com.unity.modules.screencapture) is disabled.
+                tex = s_captureScreenshotAsTextureMethod.Invoke(null, new object[] { result.SuperSize }) as Texture2D;
                 if (tex == null)
                 {
                     // Fallback to camera-based if ScreenCapture fails

MCPForUnity/Runtime/Helpers/UnityPhysicsCompat.cs

@@ -17,10 +17,15 @@ namespace MCPForUnity.Runtime.Helpers
     ///
     /// We use reflection rather than direct property access so calls stay clean of
     /// CS0618 warnings AND survive eventual removal of the obsolete property without
-    /// a recompile of this package.
+    /// a recompile of this package. Type lookups go through <see cref="Type.GetType(string)"/>
+    /// so this file compiles even when the Physics 2D built-in module is disabled in
+    /// the Package Manager.
     /// </summary>
     public static class UnityPhysicsCompat
     {
+        // Assembly-qualified name — resolved at runtime so the file compiles when the
+        // Physics 2D built-in module is disabled in the Package Manager.
+        private const string Physics2DTypeName = "UnityEngine.Physics2D, UnityEngine.Physics2DModule";
         /// <summary>
         /// Cross-version description of the 3D physics simulation mode.
         /// On 2022.2+ this maps onto <c>UnityEngine.SimulationMode</c>; on older
@@ -46,9 +51,13 @@ private static PropertyInfo Physics2DAutoSyncProp
                 if (!_physics2DProbed)
                 {
                     _physics2DProbed = true;
-                    _physics2DAutoSync = typeof(Physics2D).GetProperty(
-                        "autoSyncTransforms",
-                        BindingFlags.Public | BindingFlags.Static);
+                    var physics2DType = Type.GetType(Physics2DTypeName);
+                    if (physics2DType != null)
+                    {
+                        _physics2DAutoSync = physics2DType.GetProperty(
+                            "autoSyncTransforms",
+                            BindingFlags.Public | BindingFlags.Static);
+                    }
                 }
                 return _physics2DAutoSync;
             }