add byte counted text input

adds a new widget that counts bytes during entry

configurable limit and shows user both count and limit

provides color feedback

use new widget in chat and channel text entry

lib/screens/channel_chat_screen.dart

@@ -13,7 +13,6 @@ import '../helpers/chat_scroll_controller.dart';
 import '../connector/meshcore_protocol.dart';
 import '../helpers/gif_helper.dart';
 import '../helpers/reaction_helper.dart';
-import '../helpers/utf8_length_limiter.dart';
 import '../helpers/snack_bar_builder.dart';
 import '../l10n/l10n.dart';
 import '../models/channel.dart';
@@ -23,6 +22,7 @@ import '../services/app_settings_service.dart';
 import '../services/chat_text_scale_service.dart';
 import '../services/translation_service.dart';
 import '../utils/emoji_utils.dart';
+import '../widgets/byte_count_input.dart';
 import '../widgets/chat_zoom_wrapper.dart';
 import '../widgets/emoji_picker.dart';
 import '../widgets/gif_message.dart';
@@ -1093,27 +1093,26 @@ class _ChannelChatScreenState extends State<ChannelChatScreen> {
                         ),
                       );
                     }
-
-                    return TextField(
+                    return ByteCountedTextField(
+                      maxBytes: maxBytes,
                       controller: _textController,
                       focusNode: _textFieldFocusNode,
-                      inputFormatters: [
-                        Utf8LengthLimitingTextInputFormatter(maxBytes),
-                      ],
-                      textCapitalization: TextCapitalization.sentences,
+                      hintText: context.l10n.chat_typeMessage,
+                      onSubmitted: (_) => _sendMessage(),
                       decoration: InputDecoration(
                         hintText: context.l10n.chat_typeMessage,
                         border: OutlineInputBorder(
                           borderRadius: BorderRadius.circular(24),
                         ),
+                        filled: true,
+                        fillColor: Theme.of(
+                          context,
+                        ).colorScheme.surfaceContainerLow,
                         contentPadding: const EdgeInsets.symmetric(
-                          horizontal: 16,
-                          vertical: 8,
+                          horizontal: 20,
+                          vertical: 14,
                         ),
                       ),
-                      maxLines: null,
-                      textInputAction: TextInputAction.send,
-                      onSubmitted: (_) => _sendMessage(),
                     );
                   },
                 ),

lib/screens/chat_screen.dart

@@ -18,7 +18,6 @@ import '../widgets/message_status_icon.dart';
 import '../helpers/chat_scroll_controller.dart';
 import '../helpers/gif_helper.dart';
 import '../helpers/path_helper.dart';
-import '../helpers/utf8_length_limiter.dart';
 import '../models/channel_message.dart';
 import '../models/contact.dart';
 import '../models/message.dart';
@@ -30,6 +29,7 @@ import '../services/path_history_service.dart';
 import '../services/translation_service.dart';
 import '../widgets/chat_zoom_wrapper.dart';
 import '../widgets/elements_ui.dart';
+import '../widgets/byte_count_input.dart';
 import 'channel_message_path_screen.dart';
 import 'map_screen.dart';
 import '../utils/emoji_utils.dart';
@@ -567,24 +567,26 @@ class _ChatScreenState extends State<ChatScreen> {
                       ),
                     );
                   }
-
-                  return TextField(
+                  return ByteCountedTextField(
+                    maxBytes: maxBytes,
                     controller: _textController,
                     focusNode: _textFieldFocusNode,
-                    inputFormatters: [
-                      Utf8LengthLimitingTextInputFormatter(maxBytes),
-                    ],
-                    textCapitalization: TextCapitalization.sentences,
+                    hintText: context.l10n.chat_typeMessage,
+                    onSubmitted: (_) => _sendMessage(connector),
                     decoration: InputDecoration(
                       hintText: context.l10n.chat_typeMessage,
-                      border: const OutlineInputBorder(),
+                      border: OutlineInputBorder(
+                        borderRadius: BorderRadius.circular(24),
+                      ),
+                      filled: true,
+                      fillColor: Theme.of(
+                        context,
+                      ).colorScheme.surfaceContainerLow,
                       contentPadding: const EdgeInsets.symmetric(
-                        horizontal: 16,
-                        vertical: 12,
+                        horizontal: 20,
+                        vertical: 14,
                       ),
                     ),
-                    textInputAction: TextInputAction.send,
-                    onSubmitted: (_) => _sendMessage(connector),
                   );
                 },
               ),

lib/widgets/byte_count_input.dart

@@ -0,0 +1,125 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+import '../helpers/utf8_length_limiter.dart';
+
+/// A [TextField] that displays a live UTF-8 byte counter.
+///
+/// The counter appears below the field once the user starts typing and changes
+/// colour as the limit is approached (orange at 70 %, error-red at 90 %).
+///
+/// All standard [TextField] behaviour (focus nodes, input actions, decoration
+/// overrides, etc.) is forwarded so the widget can be dropped into any screen.
+class ByteCountedTextField extends StatelessWidget {
+  /// Maximum number of UTF-8 bytes allowed.
+  final int maxBytes;
+
+  /// Controller for the text field.
+  final TextEditingController controller;
+
+  /// Optional focus node forwarded to the inner [TextField].
+  final FocusNode? focusNode;
+
+  /// Hint text shown when the field is empty.
+  final String? hintText;
+
+  /// Keyboard action button (defaults to [TextInputAction.send]).
+  final TextInputAction textInputAction;
+
+  /// Called when the user submits via the keyboard action button.
+  final ValueChanged<String>? onSubmitted;
+
+  /// Additional [TextInputFormatter]s applied *before* the byte limiter.
+  final List<TextInputFormatter> extraFormatters;
+
+  /// Text capitalisation forwarded to the inner [TextField].
+  final TextCapitalization textCapitalization;
+
+  /// Optional full [InputDecoration] override.  When provided, [hintText] is
+  /// ignored – set it inside the decoration instead.
+  final InputDecoration? decoration;
+
+  /// Ratio (0–1) at which the counter turns the warning colour (default 0.7).
+  final double warningThreshold;
+
+  /// Ratio (0–1) at which the counter turns the error colour (default 0.9).
+  final double errorThreshold;
+
+  /// Whether to hide the counter when the field is empty (default `true`).
+  final bool hideCounterWhenEmpty;
+
+  const ByteCountedTextField({
+    super.key,
+    required this.maxBytes,
+    required this.controller,
+    this.focusNode,
+    this.hintText,
+    this.textInputAction = TextInputAction.send,
+    this.onSubmitted,
+    this.extraFormatters = const [],
+    this.textCapitalization = TextCapitalization.sentences,
+    this.decoration,
+    this.warningThreshold = 0.7,
+    this.errorThreshold = 0.9,
+    this.hideCounterWhenEmpty = true,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return ValueListenableBuilder<TextEditingValue>(
+      valueListenable: controller,
+      builder: (context, value, _) {
+        final usedBytes = utf8.encode(value.text).length;
+        final ratio = maxBytes > 0 ? usedBytes / maxBytes : 0.0;
+        final showCounter = !(hideCounterWhenEmpty && value.text.isEmpty);
+
+        final counterColor = ratio > errorThreshold
+            ? Theme.of(context).colorScheme.error
+            : ratio > warningThreshold
+            ? Colors.orange
+            : Theme.of(context).colorScheme.onSurfaceVariant;
+
+        return Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            TextField(
+              controller: controller,
+              focusNode: focusNode,
+              inputFormatters: [
+                ...extraFormatters,
+                Utf8LengthLimitingTextInputFormatter(maxBytes),
+              ],
+              textCapitalization: textCapitalization,
+              decoration:
+                  decoration ??
+                  InputDecoration(
+                    hintText: hintText,
+                    border: const OutlineInputBorder(),
+                    contentPadding: const EdgeInsets.symmetric(
+                      horizontal: 16,
+                      vertical: 12,
+                    ),
+                  ),
+              textInputAction: textInputAction,
+              onSubmitted: onSubmitted,
+            ),
+            if (showCounter)
+              Padding(
+                padding: const EdgeInsets.only(top: 4, right: 4),
+                child: Align(
+                  alignment: Alignment.centerRight,
+                  child: Text(
+                    '$usedBytes / $maxBytes',
+                    style: TextStyle(fontSize: 11, color: counterColor),
+                  ),
+                ),
+              ),
+          ],
+        );
+      },
+    );
+  }
+}