fix: use library findNodeHandle wrapper, guard view.superview nil

- Import findNodeHandle from library's utils wrapper (consistent with
  KeyboardAwareScrollView usage) instead of directly from react-native
- Add view.superview nil check in iOS windowPosition to avoid silently
  resolving with CGRectZero when superview is nil

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: thomasvo

ios/KeyboardControllerModule.mm

@@ -129,7 +129,7 @@ - (void)windowPosition:(double)viewTag
       }
     }
     UIView *view = [window viewWithTag:tag];
-    if (!view) {
+    if (!view || !view.superview) {
       reject(@"E_VIEW_NOT_FOUND", @"Could not find view for tag", nil);
       return;
     }

src/components/KeyboardAvoidingView/index.tsx

@@ -1,5 +1,5 @@
 import React, { forwardRef, useCallback, useMemo } from "react";
-import { View, findNodeHandle } from "react-native";
+import { View } from "react-native";
 import Reanimated, {
   interpolate,
   runOnUI,
@@ -10,6 +10,7 @@ import Reanimated, {
 
 import { KeyboardControllerNative } from "../../bindings";
 import { useWindowDimensions } from "../../hooks";
+import { findNodeHandle } from "../../utils/findNodeHandle";
 import useCombinedRef from "../hooks/useCombinedRef";
 
 import { useKeyboardAnimation, useTranslateAnimation } from "./hooks";