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/domain/types.go

@@ -0,0 +1,54 @@
+// Package domain defines the core business types of SnapGo.
+//
+// Design rationale:
+// - Keep this layer free of any third-party SDK or OS API.
+// - Higher layers (application, infrastructure) depend on these types,
+//   but this package depends on nothing except the Go standard library.
+// - Encapsulating data here makes the upgrade path to multiple OSS providers
+//   (Aliyun OSS, Qiniu, Tencent COS, etc.) trivial — only a new infra adapter
+//   is needed.
+package domain
+
+import (
+	"context"
+	"image"
+	"time"
+)
+
+// Screenshot represents a single captured image in PNG-encoded byte form.
+//
+// We hold the encoded bytes (not image.Image) because:
+// 1. Uploaders need a byte stream;
+// 2. Local fallback writes the same bytes to disk;
+// 3. Avoids re-encoding cost.
+type Screenshot struct {
+	PNG       []byte          // PNG-encoded payload
+	Region    image.Rectangle // The captured region in virtual screen coords
+	Width     int             // Logical width of the region
+	Height    int             // Logical height of the region
+	CreatedAt time.Time       // When the capture happened
+}
+
+// UploadResult describes the outcome of a successful upload.
+type UploadResult struct {
+	URL      string        // Public URL that was copied to the clipboard
+	Key      string        // Object key on the remote storage
+	Provider string        // Provider name, e.g. "s3"
+	Elapsed  time.Duration // How long the upload took
+}
+
+// OSSProvider is the abstraction every storage adapter MUST implement.
+//
+// Why an interface:
+// - Allows the application layer to remain agnostic of the concrete SDK.
+// - Future providers (Aliyun OSS / COS / Qiniu) only need a new adapter
+//   without touching the service layer.
+type OSSProvider interface {
+	// Upload pushes data with the given key and content-type to remote storage,
+	// returning the publicly accessible URL on success.
+	Upload(ctx context.Context, key string, data []byte, contentType string) (publicURL string, err error)
+
+	// Name returns a stable identifier of the provider implementation
+	// (used in logs, telemetry, history records).
+	Name() string
+}