fix: resolve multiple bugs found during code review

lib/core/services/app_logger.dart

@@ -1,4 +1,5 @@
 import 'dart:io';
+import 'package:flutter/foundation.dart';
 import 'package:logger/logger.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:intl/intl.dart';
@@ -38,7 +39,7 @@ class AppLogger {
       final dateStr = DateFormat('yyyy-MM-dd').format(DateTime.now());
       _logFile = File('${logsDir.path}/app_log_$dateStr.txt');
     } catch (e) {
-      print('Failed to initialize log file: $e');
+      debugPrint('Failed to initialize log file: $e');
     }
   }
 
@@ -63,7 +64,7 @@ class AppLogger {
         );
       }
     } catch (e) {
-      print('Failed to write to log file: $e');
+      debugPrint('Failed to write to log file: $e');
     }
   }
 
@@ -114,7 +115,7 @@ class _CustomOutput extends LogOutput {
   void output(OutputEvent event) {
     for (var line in event.lines) {
       appLogger._addToBuffer(line);
-      print(line);
+      debugPrint(line);
     }
   }
 }

lib/data/datasources/api/gemini_api_client.dart

@@ -42,6 +42,10 @@ class GeminiApiClient extends BaseApiClient {
         ),
         data: {
           'contents': _convertMessages(messages, systemPrompt),
+          if (systemPrompt != null && systemPrompt.isNotEmpty)
+            'systemInstruction': {
+              'parts': [{'text': systemPrompt}],
+            },
           if (tools.isNotEmpty) 'tools': [{'functionDeclarations': _convertTools(tools)}],
           'generationConfig': {
             if (maxTokens != null) 'maxOutputTokens': maxTokens,
@@ -115,14 +119,9 @@ class GeminiApiClient extends BaseApiClient {
 
   List<Map<String, dynamic>> _convertMessages(List<Message> messages, String? systemPrompt) {
     final contents = <Map<String, dynamic>>[];
-
-    // Add system prompt as first user message if provided
-    if (systemPrompt != null && systemPrompt.isNotEmpty) {
-      contents.add({
-        'role': 'user',
-        'parts': [{'text': systemPrompt}],
-      });
-    }
+
+    // System prompt is passed separately via systemInstruction in the request body,
+    // so we do not inject it as a user message here.
 
     for (final msg in messages) {
       contents.add({

lib/data/datasources/ssh/ssh_client_impl.dart

@@ -1,5 +1,6 @@
 import 'dart:async';
 import 'dart:convert';
+import 'dart:io';
 import 'package:dartssh2/dartssh2.dart';
 import '../../../core/errors/exceptions.dart';
 import '../../../core/constants/app_constants.dart';
@@ -66,7 +67,6 @@ class SSHClientImpl {
   Future<void> disconnect() async {
     try {
       _logger.info('Disconnecting from SSH server', tag: 'SSH');
-      _updateStatus(SSHConnectionStatus.disconnected);
 
       _sftpClient?.close();
       _session?.close();
@@ -195,7 +195,27 @@ class SSHClientImpl {
   }
 
   Future<String> _readPrivateKey(String path) async {
-    throw UnimplementedError('Private key reading not implemented');
+    try {
+      _logger.debug('Reading private key from: $path', tag: 'SSH');
+      // Read the private key file via SSH command on local device
+      // For mobile, the path is expected to be a local file path
+      final file = File(path);
+      if (!await file.exists()) {
+        throw SSHException(
+          message: 'Private key file not found at: $path',
+        );
+      }
+      final content = await file.readAsString();
+      _logger.debug('Private key read successfully', tag: 'SSH');
+      return content;
+    } catch (e) {
+      if (e is SSHException) rethrow;
+      _logger.error('Failed to read private key: ${e.toString()}', error: e, tag: 'SSH');
+      throw SSHException(
+        message: 'Failed to read private key file: ${e.toString()}',
+        details: e,
+      );
+    }
   }
 
   Future<void> dispose() async {

lib/data/tools/bash_tool.dart

@@ -28,10 +28,27 @@ class BashTool extends BaseTool {
   @override
   bool get isReadOnly => false;
 
+  /// Dangerous command patterns that should be blocked for safety.
+  static final _dangerousPatterns = [
+    RegExp(r'rm\s+(-[a-zA-Z]*f[a-zA-Z]*\s+)?/\s*$'),
+    RegExp(r'rm\s+-[a-zA-Z]*r[a-zA-Z]*f[a-zA-Z]*\s+/\s*$'),
+    RegExp(r'mkfs\.'),
+    RegExp(r'dd\s+.*of=/dev/'),
+    RegExp(r':(\s*)\{\s*:\|:\s*&\s*\}\s*;\s*:'),
+  ];
+
   @override
   Future<String> execute(Map<String, dynamic> arguments) async {
     final command = arguments['command'] as String;
 
+    // Check for dangerous commands
+    for (final pattern in _dangerousPatterns) {
+      if (pattern.hasMatch(command)) {
+        return 'Error: This command has been blocked for safety. '
+            'It matches a dangerous pattern that could cause data loss.';
+      }
+    }
+
     final result = await sshRepository.executeCommand(command);
 
     return result.fold(

lib/presentation/blocs/chat/chat_bloc.dart

@@ -102,8 +102,9 @@ class ChatBloc extends Bloc<ChatEvent, ChatState> {
     _logger.debug('Created user message: ${userMessage.id}', tag: 'ChatBloc');
 
     // Add user message to UI
+    final messagesWithUser = [...currentState.messages, userMessage];
     emit(currentState.copyWith(
-      messages: [...currentState.messages, userMessage],
+      messages: messagesWithUser,
     ));
 
     // Save user message
@@ -122,7 +123,7 @@ class ChatBloc extends Bloc<ChatEvent, ChatState> {
     );
 
     emit(currentState.copyWith(
-      messages: [...currentState.messages, assistantMessage],
+      messages: [...messagesWithUser, assistantMessage],
       isStreaming: true,
     ));
 
@@ -256,62 +257,63 @@ class ChatBloc extends Bloc<ChatEvent, ChatState> {
 
     final result = await loadSession(event.sessionId);
 
-    result.fold(
-      (failure) async {
-        _logger.warning('Session not found: ${event.sessionId}', tag: 'ChatBloc');
-        // If session not found, create a new one
-        if (failure.toString().contains('Session not found')) {
-          // Get connection info
-          final providersResult = await getProviders();
-          providersResult.fold(
-            (error) {
-              _logger.error('No provider configured', tag: 'ChatBloc');
-              emit(ChatError(message: 'No provider configured. Please add a provider in settings.'));
-            },
-            (providers) {
-              if (providers.isEmpty) {
-                _logger.error('No providers available', tag: 'ChatBloc');
-                emit(ChatError(message: 'No provider configured. Please add a provider in settings.'));
-                return;
-              }
-
-              final defaultProvider = providers.firstWhere(
-                (p) => p.isDefault,
-                orElse: () => providers.first,
-              );
-
-              _logger.info('Creating new session with provider: ${defaultProvider.name}', tag: 'ChatBloc');
-              // Create new session
-              final newSession = Session(
-                id: event.sessionId,
-                name: 'New Chat',
-                sshConfigId: 'default',
-                providerId: defaultProvider.id,
-                workingDirectory: '/home',
-                createdAt: DateTime.now(),
-                updatedAt: DateTime.now(),
-                messages: [],
-              );
-
-              emit(ChatLoaded(
-                session: newSession,
-                messages: [],
-              ));
-            },
-          );
-        } else {
-          _logger.error('Failed to load session: ${failure.toString()}', tag: 'ChatBloc');
-          emit(ChatError(message: failure.toString()));
-        }
-      },
-      (session) {
-        _logger.info('Session loaded successfully with ${session.messages.length} messages', tag: 'ChatBloc');
-        emit(ChatLoaded(
-          session: session,
-          messages: session.messages,
-        ));
-      },
+    if (result.isRight()) {
+      final session = result.getOrElse(() => throw StateError('unreachable'));
+      _logger.info('Session loaded successfully with ${session.messages.length} messages', tag: 'ChatBloc');
+      emit(ChatLoaded(
+        session: session,
+        messages: session.messages,
+      ));
+      return;
+    }
+
+    // Handle failure
+    final failure = result.fold((f) => f, (_) => throw StateError('unreachable'));
+    _logger.warning('Session not found: ${event.sessionId}', tag: 'ChatBloc');
+
+    if (!failure.toString().contains('Session not found')) {
+      _logger.error('Failed to load session: ${failure.toString()}', tag: 'ChatBloc');
+      emit(ChatError(message: failure.toString()));
+      return;
+    }
+
+    // Session not found — create a new one
+    final providersResult = await getProviders();
+
+    if (providersResult.isLeft()) {
+      _logger.error('No provider configured', tag: 'ChatBloc');
+      emit(ChatError(message: 'No provider configured. Please add a provider in settings.'));
+      return;
+    }
+
+    final providers = providersResult.getOrElse(() => []);
+    if (providers.isEmpty) {
+      _logger.error('No providers available', tag: 'ChatBloc');
+      emit(ChatError(message: 'No provider configured. Please add a provider in settings.'));
+      return;
+    }
+
+    final defaultProvider = providers.firstWhere(
+      (p) => p.isDefault,
+      orElse: () => providers.first,
     );
+
+    _logger.info('Creating new session with provider: ${defaultProvider.name}', tag: 'ChatBloc');
+    final newSession = Session(
+      id: event.sessionId,
+      name: 'New Chat',
+      sshConfigId: 'default',
+      providerId: defaultProvider.id,
+      workingDirectory: '/home',
+      createdAt: DateTime.now(),
+      updatedAt: DateTime.now(),
+      messages: [],
+    );
+
+    emit(ChatLoaded(
+      session: newSession,
+      messages: [],
+    ));
   }
 
   List<Tool> _getAvailableTools() {