feat: custom native file picker showing hidden files/folders

Replaced file_picker's Load/Browse with a custom NativePickerRegistrar
Swift plugin that opens NSOpenPanel with showsHiddenFiles = true.
The file_picker package hardcodes this to false, making hidden folders
like ~/.claude invisible in its dialogs.

Changes:
- New NativePickerRegistrar.swift: custom NSOpenPanel with hidden files
- New NativePicker Dart service using method channel
- Browse: only shows folders (canChooseFiles=false), hidden visible
- Load: only shows .jsonl files, hidden folders visible
- Registered via AppDelegate.applicationDidFinishLaunching
- Removed file_picker dependency from home_screen imports
- Fixed all info-level lint issues (super params, null-aware, doc comment)
- Signed, notarized, stapled DMG

lib/models/content_block.dart

@@ -22,8 +22,8 @@ class ContentBlock {
 class TextBlock extends ContentBlock {
   final String text;
 
-  TextBlock({required this.text, required Map<String, dynamic> raw})
+  TextBlock({required this.text, required super.raw})
-      : super(type: 'text', raw: raw);
+      : super(type: 'text');
 
   factory TextBlock.fromJson(Map<String, dynamic> json) {
     return TextBlock(
@@ -40,8 +40,8 @@ class ThinkingBlock extends ContentBlock {
   ThinkingBlock({
     required this.thinking,
     this.signature,
-    required Map<String, dynamic> raw,
+    required super.raw,
-  }) : super(type: 'thinking', raw: raw);
+  }) : super(type: 'thinking');
 
   factory ThinkingBlock.fromJson(Map<String, dynamic> json) {
     return ThinkingBlock(
@@ -63,8 +63,8 @@ class ToolUseBlock extends ContentBlock {
     required this.name,
     required this.input,
     this.linkedResult,
-    required Map<String, dynamic> raw,
+    required super.raw,
-  }) : super(type: 'tool_use', raw: raw);
+  }) : super(type: 'tool_use');
 
   factory ToolUseBlock.fromJson(Map<String, dynamic> json) {
     return ToolUseBlock(

lib/screens/home/home_screen.dart

@@ -1,8 +1,8 @@
 import 'dart:io';
-import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import '../../providers/session_provider.dart';
+import '../../services/native_picker.dart';
 import '../../theme/app_theme.dart';
 
 // ─── Data models ─────────────────────────────────────────────
@@ -120,7 +120,7 @@ class _HomeScreenState extends State<HomeScreen> {
   }
 
   /// Returns the real user home directory, even inside App Sandbox.
-  /// In sandbox, HOME points to ~/Library/Containers/<bundleid>/Data.
+  /// In sandbox, HOME points to `~/Library/Containers/bundleid/Data`.
   String? _getRealHome() {
     final home = Platform.environment['HOME'];
     if (home == null) return null;
@@ -333,8 +333,9 @@ class _HomeScreenState extends State<HomeScreen> {
 
   Future<void> _pickFolder() async {
     try {
-      final result = await FilePicker.platform.getDirectoryPath(
+      final home = _getRealHome() ?? '';
-        dialogTitle: 'Select a folder containing Claude session files',
+      final result = await NativePicker.getDirectoryPath(
+        initialDirectory: '$home/.claude/projects',
       );
       if (result != null) {
         _pathController.text = result;
@@ -407,13 +408,13 @@ class _HomeScreenState extends State<HomeScreen> {
 
   Future<void> _loadSingleFile() async {
     try {
-      final result = await FilePicker.platform.pickFiles(
+      final home = _getRealHome() ?? '';
-        type: FileType.custom,
+      final result = await NativePicker.pickFile(
         allowedExtensions: ['jsonl'],
-        dialogTitle: 'Select a Claude session file (.jsonl)',
+        initialDirectory: '$home/.claude/projects',
       );
-      if (result != null && result.files.single.path != null) {
+      if (result != null) {
-        await _loadFile(result.files.single.path!);
+        await _loadFile(result);
       }
     } catch (e) {
       debugPrint('[Load] Error: $e');

lib/services/native_picker.dart

@@ -0,0 +1,41 @@
+import 'package:flutter/services.dart';
+
+/// Native file picker that shows hidden files/folders on macOS.
+/// Uses a custom method channel to NSOpenPanel with showsHiddenFiles = true,
+/// which the file_picker package hardcodes to false.
+class NativePicker {
+  static const _channel = MethodChannel('com.svrnty.native_picker');
+
+  /// Opens a folder picker that shows hidden directories.
+  /// Returns the selected folder path, or null if cancelled.
+  static Future<String?> getDirectoryPath({String? initialDirectory}) async {
+    try {
+      return _channel.invokeMethod<String?>('getDirectoryPath', {
+        'initialDirectory': initialDirectory,
+      });
+    } on PlatformException catch (e) {
+      throw Exception('Native picker error: ${e.message}');
+    }
+  }
+
+  /// Opens a file picker that shows hidden files, filtered to specific extensions.
+  /// Returns the selected file path, or null if cancelled.
+  static Future<String?> pickFile({
+    List<String> allowedExtensions = const [],
+    String? initialDirectory,
+  }) async {
+    try {
+      final result = await _channel.invokeMethod<List?>('pickFiles', {
+        'allowMultiple': false,
+        'allowedExtensions': allowedExtensions,
+        'initialDirectory': initialDirectory,
+      });
+      if (result != null && result.isNotEmpty) {
+        return result.first as String;
+      }
+      return null;
+    } on PlatformException catch (e) {
+      throw Exception('Native picker error: ${e.message}');
+    }
+  }
+}

macos/Runner.xcodeproj/project.pbxproj

@@ -24,6 +24,7 @@
 		331C80D8294CF71000263BE5 /* RunnerTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 331C80D7294CF71000263BE5 /* RunnerTests.swift */; };
 		335BBD1B22A9A15E00E9071D /* GeneratedPluginRegistrant.swift in Sources */ = {isa = PBXBuildFile; fileRef = 335BBD1A22A9A15E00E9071D /* GeneratedPluginRegistrant.swift */; };
 		33CC10F12044A3C60003C045 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 33CC10F02044A3C60003C045 /* AppDelegate.swift */; };
+		AABB001B1B1B1B1B1B1B /* NativePickerRegistrar.swift in Sources */ = {isa = PBXBuildFile; fileRef = AABB001A1A1A1A1A1A1A /* NativePickerRegistrar.swift */; };
 		33CC10F32044A3C60003C045 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 33CC10F22044A3C60003C045 /* Assets.xcassets */; };
 		33CC10F62044A3C60003C045 /* MainMenu.xib in Resources */ = {isa = PBXBuildFile; fileRef = 33CC10F42044A3C60003C045 /* MainMenu.xib */; };
 		33CC10FF2044A3C60003C045 /* PrivacyInfo.xcprivacy in Resources */ = {isa = PBXBuildFile; fileRef = 33CC10FE2044A3C60003C045 /* PrivacyInfo.xcprivacy */; };
@@ -68,6 +69,7 @@
 		335BBD1A22A9A15E00E9071D /* GeneratedPluginRegistrant.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = GeneratedPluginRegistrant.swift; sourceTree = "<group>"; };
 		33CC10ED2044A3C60003C045 /* Claude Session Analysis.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = "Claude Session Analysis.app"; sourceTree = BUILT_PRODUCTS_DIR; };
 		33CC10F02044A3C60003C045 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
+		AABB001A1A1A1A1A1A1A /* NativePickerRegistrar.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NativePickerRegistrar.swift; sourceTree = "<group>"; };
 		33CC10F22044A3C60003C045 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; name = Assets.xcassets; path = Runner/Assets.xcassets; sourceTree = "<group>"; };
 		33CC10F52044A3C60003C045 /* Base */ = {isa = PBXFileReference; lastKnownFileType = file.xib; name = Base; path = Base.lproj/MainMenu.xib; sourceTree = "<group>"; };
 		33CC10F72044A3C60003C045 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; name = Info.plist; path = Runner/Info.plist; sourceTree = "<group>"; };
@@ -168,6 +170,7 @@
 			isa = PBXGroup;
 			children = (
 				33CC10F02044A3C60003C045 /* AppDelegate.swift */,
+				AABB001A1A1A1A1A1A1A /* NativePickerRegistrar.swift */,
 				33CC11122044BFA00003C045 /* MainFlutterWindow.swift */,
 				33CC10FE2044A3C60003C045 /* PrivacyInfo.xcprivacy */,
 				33E51913231747F40026EE4D /* DebugProfile.entitlements */,
@@ -352,6 +355,7 @@
 			files = (
 				33CC11132044BFA00003C045 /* MainFlutterWindow.swift in Sources */,
 				33CC10F12044A3C60003C045 /* AppDelegate.swift in Sources */,
+				AABB001B1B1B1B1B1B1B /* NativePickerRegistrar.swift in Sources */,
 				335BBD1B22A9A15E00E9071D /* GeneratedPluginRegistrant.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;

macos/Runner/AppDelegate.swift

@@ -10,4 +10,13 @@ class AppDelegate: FlutterAppDelegate {
   override func applicationSupportsSecureRestorableState(_ app: NSApplication) -> Bool {
     return true
   }
+
+  override func applicationDidFinishLaunching(_ notification: Notification) {
+    // Register our custom native picker that shows hidden files
+    // This is called before Flutter engine starts
+    if let controller = mainFlutterWindow?.contentViewController as? FlutterViewController {
+      NativePickerRegistrar.register(with: controller.registrar(forPlugin: "NativePickerRegistrar"))
+    }
+    super.applicationDidFinishLaunching(notification)
+  }
 }

macos/Runner/NativePickerRegistrar.swift

@@ -0,0 +1,84 @@
+import Cocoa
+import FlutterMacOS
+import UniformTypeIdentifiers
+
+/// Registers a method channel for native file picking with hidden files visible.
+/// Called from Dart via `ensureInitialized`.
+class NativePickerRegistrar: NSObject, FlutterPlugin {
+    public static func register(with registrar: FlutterPluginRegistrar) {
+        let channel = FlutterMethodChannel(
+            name: "com.svrnty.native_picker",
+            binaryMessenger: registrar.messenger)
+        let instance = NativePickerRegistrar()
+        registrar.addMethodCallDelegate(instance, channel: channel)
+    }
+
+    public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+        switch call.method {
+        case "getDirectoryPath":
+            let args = call.arguments as? [String: Any] ?? [:]
+            let dialog = NSOpenPanel()
+
+            if let initial = args["initialDirectory"] as? String, !initial.isEmpty {
+                dialog.directoryURL = URL(fileURLWithPath: initial)
+            }
+            dialog.showsHiddenFiles = true
+            dialog.canChooseDirectories = true
+            dialog.canChooseFiles = false
+            dialog.allowsMultipleSelection = false
+            dialog.treatsFilePackagesAsDirectories = true
+            dialog.message = "Select a folder containing session files"
+
+            guard let window = NSApp.keyWindow else {
+                result(FlutterError(code: "NO_WINDOW", message: "No key window found", details: nil))
+                return
+            }
+
+            dialog.beginSheetModal(for: window) { response in
+                if response == .OK, let url = dialog.url {
+                    result(url.path)
+                } else {
+                    result(nil)
+                }
+            }
+
+        case "pickFiles":
+            let args = call.arguments as? [String: Any] ?? [:]
+            let dialog = NSOpenPanel()
+
+            if let initial = args["initialDirectory"] as? String, !initial.isEmpty {
+                dialog.directoryURL = URL(fileURLWithPath: initial)
+            }
+            dialog.showsHiddenFiles = true
+            dialog.canChooseDirectories = false
+            dialog.canChooseFiles = true
+            dialog.allowsMultipleSelection = false
+
+            if let extensions = args["allowedExtensions"] as? [String], !extensions.isEmpty {
+                if #available(macOS 11.0, *) {
+                    let contentTypes = extensions.compactMap { UTType(filenameExtension: $0) }
+                    dialog.allowedContentTypes = contentTypes
+                } else {
+                    dialog.allowedFileTypes = extensions
+                }
+            }
+            dialog.message = "Select a session file"
+
+            guard let window = NSApp.keyWindow else {
+                result(FlutterError(code: "NO_WINDOW", message: "No key window found", details: nil))
+                return
+            }
+
+            dialog.beginSheetModal(for: window) { response in
+                if response == .OK, let url = dialog.url {
+                    result([url.path])
+                } else {
+                    result(nil)
+                }
+            }
+
+        default:
+            result(FlutterMethodNotImplemented)
+        }
+    }
+}