Fix keyboard input on Flutter 3.32+ by passing viewId to TextInputConfiguration

Flutter 3.32 requires a valid viewId when creating TextInputConnection.
Without it, keyboard input silently fails with PlatformException.
Falls back to PlatformDispatcher.instance.implicitView.viewId.

Based on PR TerminalStudio#210 by cnayan.

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

Author: mqtik

lib/src/ui/custom_text_edit.dart

@@ -1,3 +1,5 @@
+import 'dart:ui';
+
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
@@ -15,11 +17,17 @@ class CustomTextEdit extends StatefulWidget {
     this.autofocus = false,
     this.readOnly = false,
     // this.initEditingState = TextEditingValue.empty,
+    this.viewId,
     this.inputType = TextInputType.text,
     this.inputAction = TextInputAction.newline,
     this.keyboardAppearance = Brightness.light,
     this.deleteDetection = false,
-  });
+  }) {
+    viewId = viewId ?? PlatformDispatcher.instance.implicitView?.viewId;
+    if (viewId == null) {
+      throw Exception('Cannot open input connection without a valid viewId.');
+    }
+  }
 
   final Widget child;
 
@@ -47,6 +55,8 @@ class CustomTextEdit extends StatefulWidget {
 
   final bool deleteDetection;
 
+  late int? viewId;
+
   @override
   CustomTextEditState createState() => CustomTextEditState();
 }
@@ -160,6 +170,7 @@ class CustomTextEditState extends State<CustomTextEdit> with TextInputClient {
       _connection!.show();
     } else {
       final config = TextInputConfiguration(
+        viewId: widget.viewId,
         inputType: widget.inputType,
         inputAction: widget.inputAction,
         keyboardAppearance: widget.keyboardAppearance,