feat(app): implement basic function

General
- 配置界面支持配置对象存储桶
- 快捷键进入截图
- 一键上传截图 & 复制截图链接

MacOS
- 状态栏指示器和应用图标

overlay_window_other.go

@@ -0,0 +1,10 @@
+//go:build !darwin
+
+package main
+
+// configureOverlayWindow is a macOS-only AppKit refinement. Other platforms
+// rely on Wails' own frameless/always-on-top window behaviour.
+func configureOverlayWindow() {}
+
+// restoreOverlayWindow is a macOS-only AppKit refinement.
+func restoreOverlayWindow() {}