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

internal/infrastructure/clipboard/clipboard.go

@@ -0,0 +1,46 @@
+// Package clipboard wraps golang.design/x/clipboard with lazy initialization.
+//
+// Why a wrapper:
+// - The upstream library requires a one-time clipboard.Init() call. Hiding it
+//   here keeps the application service free of init concerns.
+// - Allows future swap to a different backend (e.g. atotto/clipboard) without
+//   changing callers.
+package clipboard
+
+import (
+	"fmt"
+	"sync"
+
+	"golang.design/x/clipboard"
+)
+
+// Writer abstracts clipboard writes for testability.
+type Writer interface {
+	WriteText(s string) error
+}
+
+type clipWriter struct {
+	once    sync.Once
+	initErr error
+}
+
+// New returns a process-wide clipboard writer. Initialization is lazy.
+func New() Writer {
+	return &clipWriter{}
+}
+
+func (w *clipWriter) ensureInit() error {
+	w.once.Do(func() {
+		w.initErr = clipboard.Init()
+	})
+	return w.initErr
+}
+
+// WriteText replaces the clipboard contents with the supplied UTF-8 string.
+func (w *clipWriter) WriteText(s string) error {
+	if err := w.ensureInit(); err != nil {
+		return fmt.Errorf("clipboard init: %w", err)
+	}
+	clipboard.Write(clipboard.FmtText, []byte(s))
+	return nil
+}