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

activation_policy_other.go

@@ -0,0 +1,12 @@
+//go:build !darwin
+
+package main
+
+// installActivationPolicyHooks is only meaningful on macOS.
+func installActivationPolicyHooks() {}
+
+// showDockIcon is only meaningful on macOS.
+func showDockIcon(_ bool) {}
+
+// hideDockIcon is only meaningful on macOS.
+func hideDockIcon() {}