chore: 添加 macOS/Web 平台支持 + 修复编译错误 + 开发环境文档

- 修复 CardTheme → CardThemeData（Flutter 3.41 API 变更）
- 修复 finance_screen 缺少 FormDialog import
- 修复工具栏 Row overflow（添加横向滚动）
- flutter create --platforms=macos,web 生成平台配置
- 添加 docs/dev-setup.md：完整开发环境配置指南
  含 Go/Flutter/Docker 安装、已知 macOS 26 兼容问题及解决方案

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/macos/Runner/MainFlutterWindow.swift

@@ -0,0 +1,15 @@
+import Cocoa
+import FlutterMacOS
+
+class MainFlutterWindow: NSWindow {
+  override func awakeFromNib() {
+    let flutterViewController = FlutterViewController()
+    let windowFrame = self.frame
+    self.contentViewController = flutterViewController
+    self.setFrame(windowFrame, display: true)
+
+    RegisterGeneratedPlugins(registry: flutterViewController)
+
+    super.awakeFromNib()
+  }
+}