refactor: improve chat input and message list layout, enhance keyboard visibility handling

lib/features/chat/views/chat_page.dart

@@ -9,7 +9,6 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_animate/flutter_animate.dart';
 import 'dart:io' show Platform, File;
 import 'dart:async';
-import 'dart:ui' show ImageFilter;
 import '../../../core/providers/app_providers.dart';
 import '../providers/chat_providers.dart';
 import '../../../core/utils/debug_logger.dart';
@@ -941,6 +940,9 @@ class _ChatPageState extends ConsumerState<ChatPage> {
     // Watch reviewer mode and auto-select model if needed
     final isReviewerMode = ref.watch(reviewerModeProvider);
 
+    // Keyboard visibility
+    final keyboardVisible = MediaQuery.of(context).viewInsets.bottom > 0;
+
     // Auto-select model when in reviewer mode with no selection
     if (isReviewerMode && selectedModel == null) {
       WidgetsBinding.instance.addPostFrameCallback((_) {
@@ -1340,10 +1342,12 @@ class _ChatPageState extends ConsumerState<ChatPage> {
                         behavior: HitTestBehavior.opaque,
                         onTap: () =>
                             FocusManager.instance.primaryFocus?.unfocus(),
+                        child: RepaintBoundary(
                           child: _buildMessagesList(theme),
                         ),
                       ),
                     ),
+                  ),
 
                   // File attachments
                   const FileAttachmentWidget(),
@@ -1352,7 +1356,8 @@ class _ChatPageState extends ConsumerState<ChatPage> {
                   const ChatOfflineOverlay(),
 
                   // Modern Input (root matches input background including safe area)
-                  ModernChatInput(
+                  RepaintBoundary(
+                    child: ModernChatInput(
                       enabled:
                           selectedModel != null &&
                           (isOnline || ref.watch(reviewerModeProvider)),
@@ -1364,6 +1369,7 @@ class _ChatPageState extends ConsumerState<ChatPage> {
                       onCameraCapture: () =>
                           _handleImageAttachment(fromCamera: true),
                     ),
+                  ),
                 ],
               ),
 
@@ -1390,14 +1396,13 @@ class _ChatPageState extends ConsumerState<ChatPage> {
                   },
                   child:
                       (_showScrollToBottom &&
+                          !keyboardVisible &&
                           ref.watch(chatMessagesProvider).isNotEmpty)
                       ? ClipRRect(
                           key: const ValueKey('scroll_to_bottom_visible'),
                           borderRadius: BorderRadius.circular(
                             AppBorderRadius.floatingButton,
                           ),
-                          child: BackdropFilter(
-                            filter: ImageFilter.blur(sigmaX: 10, sigmaY: 10),
                           child: Container(
                             decoration: BoxDecoration(
                               color: context
@@ -1431,7 +1436,6 @@ class _ChatPageState extends ConsumerState<ChatPage> {
                               ),
                             ),
                           ),
-                          ),
                         )
                       : const SizedBox.shrink(
                           key: ValueKey('scroll_to_bottom_hidden'),

lib/features/chat/widgets/modern_chat_input.dart

@@ -231,7 +231,6 @@ class _ModernChatInputState extends ConsumerState<ModernChatInput>
         children: [
           // Main input area with unified 2-row design
           Container(
-            clipBehavior: Clip.antiAlias,
             decoration: BoxDecoration(
               color: context.conduitTheme.inputBackground,
               borderRadius: const BorderRadius.vertical(
@@ -269,6 +268,7 @@ class _ModernChatInputState extends ConsumerState<ModernChatInput>
                   alignment: Alignment.topCenter,
                   child: SingleChildScrollView(
                     physics: const ClampingScrollPhysics(),
+                    child: RepaintBoundary(
                       child: Column(
                         mainAxisSize: MainAxisSize.min,
                         children: [
@@ -324,10 +324,12 @@ class _ModernChatInputState extends ConsumerState<ModernChatInput>
                                           TextCapitalization.sentences,
                                       textInputAction: TextInputAction.newline,
                                       showCursor: true,
-                                    cursorColor: context.conduitTheme.inputText,
+                                      cursorColor:
+                                          context.conduitTheme.inputText,
                                       style: AppTypography.chatMessageStyle
                                           .copyWith(
-                                          color: context.conduitTheme.inputText,
+                                            color:
+                                                context.conduitTheme.inputText,
                                           ),
                                       decoration: InputDecoration(
                                         hintText: AppLocalizations.of(
@@ -497,7 +499,8 @@ class _ModernChatInputState extends ConsumerState<ModernChatInput>
                                             const double buttonSize =
                                                 TouchTarget.comfortable;
                                             final double t = _isRecording
-                                              ? (_intensity.clamp(0, 10) / 10.0)
+                                                ? (_intensity.clamp(0, 10) /
+                                                      10.0)
                                                 : 0.0;
                                             final double ringMaxExtra = 16.0;
                                             final double ringSize =
@@ -575,7 +578,8 @@ class _ModernChatInputState extends ConsumerState<ModernChatInput>
                                         icon: Icons.bug_report,
                                         onTap: widget.enabled
                                             ? () async {
-                                              final result = await _voiceService
+                                                final result =
+                                                    await _voiceService
                                                         .testOnDeviceStt();
                                                 if (context.mounted) {
                                                   ScaffoldMessenger.of(
@@ -609,6 +613,7 @@ class _ModernChatInputState extends ConsumerState<ModernChatInput>
                 ),
               ),
             ),
+          ),
         ],
       ),
     );