feat: Implement accessible SFTP file browser and native editor

lib/ui/views/connection_view.dart

@@ -23,8 +23,11 @@ class _ConnectionViewState extends ConsumerState<ConnectionView> {
     // Listen for global connection errors (e.g. lost connection)
     ref.listen<String?>(connectionErrorProvider, (previous, next) {
       if (next != null) {
-        _showErrorDialog(next);
-        ref.read(connectionErrorProvider.notifier).state = null;
+        SemanticsService.sendAnnouncement(
+          View.of(context),
+          next,
+          TextDirection.ltr,
+        );
       }
     });
 
@@ -252,6 +255,7 @@ class _NewConnectionFormState extends ConsumerState<NewConnectionForm> {
   }
 
   Future<void> _pickKeyFile() async {
+    final view = View.of(context);
     try {
       FilePickerResult? result = await FilePicker.platform.pickFiles(
         type: FileType.any, // SSH keys often have no extension or .pem/.key
@@ -265,7 +269,11 @@ class _NewConnectionFormState extends ConsumerState<NewConnectionForm> {
             _privateKeyContent = content;
             _privateKeyName = file.name;
           });
-          SemanticsService.announce('Key selected: ${file.name}', TextDirection.ltr);
+          SemanticsService.sendAnnouncement(
+            view,
+            'Key selected: ${file.name}',
+            TextDirection.ltr,
+          );
         }
       }
     } catch (e) {

lib/ui/views/file_browser_view.dart

@@ -0,0 +1,172 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:accessible_terminal/state/terminal_provider.dart';
+import 'package:dartssh2/dartssh2.dart';
+import 'file_editor_view.dart';
+
+class FileBrowserView extends ConsumerStatefulWidget {
+  final String initialPath;
+  const FileBrowserView({super.key, this.initialPath = '.'});
+
+  @override
+  ConsumerState<FileBrowserView> createState() => _FileBrowserViewState();
+}
+
+class _FileBrowserViewState extends ConsumerState<FileBrowserView> {
+  late String _currentPath;
+  List<SftpName>? _files;
+  bool _isLoading = true;
+  String? _error;
+
+  @override
+  void initState() {
+    super.initState();
+    _currentPath = widget.initialPath;
+    _loadDirectory();
+  }
+
+  Future<void> _loadDirectory() async {
+    setState(() {
+      _isLoading = true;
+      _error = null;
+    });
+
+    try {
+      final sshService = ref.read(sshServiceProvider);
+      final files = await sshService.listDirectory(_currentPath);
+      
+      // Sort: Directories first, then alphabetically
+      files.sort((a, b) {
+        if (a.attr.isDirectory && !b.attr.isDirectory) return -1;
+        if (!a.attr.isDirectory && b.attr.isDirectory) return 1;
+        return a.filename.toLowerCase().compareTo(b.filename.toLowerCase());
+      });
+
+      if (mounted) {
+        setState(() {
+          _files = files.where((f) => f.filename != '.' && f.filename != '..').toList();
+          _isLoading = false;
+        });
+      }
+    } catch (e) {
+      if (mounted) {
+        setState(() {
+          _error = e.toString();
+          _isLoading = false;
+        });
+      }
+    }
+  }
+
+  void _navigate(String filename) {
+    setState(() {
+      if (_currentPath == '/') {
+        _currentPath = '/$filename';
+      } else {
+        _currentPath = '$_currentPath/$filename'.replaceAll('//', '/');
+      }
+    });
+    _loadDirectory();
+  }
+
+  void _goUp() {
+    if (_currentPath == '/' || _currentPath == '.') return;
+    final parts = _currentPath.split('/');
+    parts.removeLast();
+    setState(() {
+      _currentPath = parts.isEmpty ? '/' : parts.join('/');
+      if (_currentPath.isEmpty) _currentPath = '/';
+    });
+    _loadDirectory();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(_currentPath),
+        actions: [
+          IconButton(
+            icon: const Icon(Icons.refresh),
+            onPressed: _loadDirectory,
+            tooltip: 'Refresh',
+          ),
+        ],
+      ),
+      body: _buildBody(),
+    );
+  }
+
+  Widget _buildBody() {
+    if (_isLoading) {
+      return const Center(child: CircularProgressIndicator());
+    }
+
+    if (_error != null) {
+      return Center(
+        child: Padding(
+          padding: const EdgeInsets.all(16.0),
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              const Icon(Icons.error, color: Colors.red, size: 48),
+              const SizedBox(height: 16),
+              Text('Error: $_error', textAlign: TextAlign.center),
+              const SizedBox(height: 16),
+              ElevatedButton(onPressed: _loadDirectory, child: const Text('Retry')),
+            ],
+          ),
+        ),
+      );
+    }
+
+    return Column(
+      children: [
+        if (_currentPath != '/' && _currentPath != '.')
+          ListTile(
+            leading: const Icon(Icons.arrow_upward),
+            title: const Text('.. (Go Up)'),
+            onTap: _goUp,
+          ),
+        Expanded(
+          child: ListView.builder(
+            itemCount: _files?.length ?? 0,
+            itemBuilder: (context, index) {
+              final file = _files![index];
+              final isDir = file.attr.isDirectory;
+
+              return ListTile(
+                leading: Icon(isDir ? Icons.folder : Icons.insert_drive_file),
+                title: Text(file.filename),
+                subtitle: isDir ? null : Text(_formatSize(file.attr.size ?? 0)),
+                onTap: () {
+                  if (isDir) {
+                    _navigate(file.filename);
+                  } else {
+                    _openFile(file.filename);
+                  }
+                },
+              );
+            },
+          ),
+        ),
+      ],
+    );
+  }
+
+  String _formatSize(int bytes) {
+    if (bytes < 1024) return '$bytes B';
+    if (bytes < 1024 * 1024) return '${(bytes / 1024).toStringAsFixed(1)} KB';
+    return '${(bytes / (1024 * 1024)).toStringAsFixed(1)} MB';
+  }
+
+  void _openFile(String filename) {
+    final fullPath = _currentPath == '/' ? '/$filename' : '$_currentPath/$filename';
+    Navigator.push(
+      context,
+      MaterialPageRoute(
+        builder: (context) => FileEditorView(path: fullPath),
+      ),
+    ).then((_) => _loadDirectory()); // Refresh on return in case of changes
+  }
+}

lib/ui/views/file_editor_view.dart

@@ -0,0 +1,147 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:accessible_terminal/state/terminal_provider.dart';
+
+class FileEditorView extends ConsumerStatefulWidget {
+  final String path;
+  const FileEditorView({super.key, required this.path});
+
+  @override
+  ConsumerState<FileEditorView> createState() => _FileEditorViewState();
+}
+
+class _FileEditorViewState extends ConsumerState<FileEditorView> {
+  final TextEditingController _controller = TextEditingController();
+  bool _isLoading = true;
+  bool _isSaving = false;
+  String? _error;
+
+  @override
+  void initState() {
+    super.initState();
+    _loadFile();
+  }
+
+  Future<void> _loadFile() async {
+    setState(() {
+      _isLoading = true;
+      _error = null;
+    });
+
+    try {
+      final sshService = ref.read(sshServiceProvider);
+      final content = await sshService.readFile(widget.path);
+      if (mounted) {
+        setState(() {
+          _controller.text = content;
+          _isLoading = false;
+        });
+      }
+    } catch (e) {
+      String errorMessage = e.toString();
+      if (e is FormatException) {
+        errorMessage = 'This file appears to be binary or uses an unsupported encoding. Cannot edit as text.';
+      }
+      
+      if (mounted) {
+        setState(() {
+          _error = errorMessage;
+          _isLoading = false;
+        });
+      }
+    }
+  }
+
+  Future<void> _saveFile() async {
+    setState(() {
+      _isSaving = true;
+    });
+
+    try {
+      final sshService = ref.read(sshServiceProvider);
+      await sshService.writeFile(widget.path, _controller.text);
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          const SnackBar(content: Text('File saved successfully')),
+        );
+        Navigator.pop(context);
+      }
+    } catch (e) {
+      if (mounted) {
+        setState(() {
+          _isSaving = false;
+        });
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(content: Text('Error saving file: $e'), backgroundColor: Colors.red),
+        );
+      }
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final fileName = widget.path.split('/').last;
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('Editing: $fileName'),
+        actions: [
+          if (!_isLoading && _error == null)
+            IconButton(
+              icon: _isSaving 
+                ? const SizedBox(width: 24, height: 24, child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white))
+                : const Icon(Icons.save),
+              onPressed: _isSaving ? null : _saveFile,
+              tooltip: 'Save File',
+            ),
+        ],
+      ),
+      body: _buildBody(),
+    );
+  }
+
+  Widget _buildBody() {
+    if (_isLoading) {
+      return const Center(child: CircularProgressIndicator());
+    }
+
+    if (_error != null) {
+      return Center(
+        child: Padding(
+          padding: const EdgeInsets.all(16.0),
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              const Icon(Icons.error, color: Colors.red, size: 48),
+              const SizedBox(height: 16),
+              Text('Error: $_error', textAlign: TextAlign.center),
+              const SizedBox(height: 16),
+              ElevatedButton(onPressed: _loadFile, child: const Text('Retry')),
+            ],
+          ),
+        ),
+      );
+    }
+
+    return Padding(
+      padding: const EdgeInsets.all(8.0),
+      child: Semantics(
+        label: 'File content editor',
+        multiline: true,
+        child: TextField(
+          controller: _controller,
+          maxLines: null,
+          expands: true,
+          textAlignVertical: TextAlignVertical.top,
+          autocorrect: false,
+          enableSuggestions: false,
+          style: const TextStyle(fontFamily: 'monospace', fontSize: 16),
+          decoration: const InputDecoration(
+            border: OutlineInputBorder(),
+            hintText: 'Enter file content...',
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/ui/views/terminal_view.dart

@@ -6,6 +6,7 @@ import 'package:wakelock_plus/wakelock_plus.dart';
 import 'package:accessible_terminal/state/terminal_provider.dart';
 import 'package:accessible_terminal/models/terminal_line.dart';
 import 'package:accessible_terminal/ui/widgets/ansi_text_parser.dart';
+import 'package:accessible_terminal/ui/views/file_browser_view.dart';
 
 class TerminalView extends ConsumerStatefulWidget {
   const TerminalView({super.key});
@@ -114,7 +115,11 @@ class _TerminalViewState extends ConsumerState<TerminalView> {
         final newLine = next.first;
         final cleanText = AnsiTextParser.strip(newLine.text);
         if (cleanText.trim().isNotEmpty) {
-          SemanticsService.announce(cleanText, TextDirection.ltr);
+          SemanticsService.sendAnnouncement(
+            View.of(context),
+            cleanText,
+            TextDirection.ltr,
+          );
         }
       }
     });
@@ -135,6 +140,19 @@ class _TerminalViewState extends ConsumerState<TerminalView> {
               ),
             ],
           ),
+          Semantics(
+            label: 'Open File Browser',
+            button: true,
+            child: IconButton(
+              icon: const Icon(Icons.folder_open),
+              onPressed: () {
+                Navigator.push(
+                  context,
+                  MaterialPageRoute(builder: (context) => const FileBrowserView()),
+                );
+              },
+            ),
+          ),
           Semantics(
             label: 'Disconnect',
             button: true,