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/config.go

@@ -0,0 +1,61 @@
+// Package domain — configuration types.
+//
+// S3Config is intentionally split into its own file so that future providers
+// can introduce their own configuration types side-by-side without polluting
+// the core domain types file.
+package domain
+
+// S3Config describes the connection parameters for any S3-compatible
+// endpoint (AWS S3, MinIO, Cloudflare R2, Backblaze B2, Aliyun OSS S3
+// endpoint, etc.).
+//
+// Field design notes:
+// - PathPrefix supports object name templating so users can group screenshots
+//   by date.
+// - PublicURLBase is optional to support CDN-fronted buckets; otherwise the
+//   adapter falls back to "{Endpoint}/{Bucket}/{Key}" (path-style).
+// - UsePathStyle defaults to true because many self-hosted MinIO / R2
+//   deployments do not support virtual-hosted-style addressing.
+type S3Config struct {
+	Endpoint        string `json:"endpoint"`
+	Region          string `json:"region"`
+	Bucket          string `json:"bucket"`
+	AccessKeyID     string `json:"accessKeyId"`
+	SecretAccessKey string `json:"secretAccessKey"`
+	PathPrefix      string `json:"pathPrefix"`
+	PublicURLBase   string `json:"publicUrlBase"`
+	UsePathStyle    bool   `json:"usePathStyle"`
+}
+
+// AppConfig is the top-level on-disk configuration document.
+//
+// We keep S3 nested so that adding more providers later (e.g. AliyunOSS, COS)
+// only requires a new sibling field rather than a schema rewrite.
+type AppConfig struct {
+	// Hotkey describes the global shortcut that triggers a capture.
+	// Stored as a human-readable string like "cmd+shift+a"; parsing happens
+	// in the infrastructure hotkey adapter.
+	Hotkey string `json:"hotkey"`
+
+	// S3 holds the active S3-compatible storage configuration.
+	S3 S3Config `json:"s3"`
+}
+
+// DefaultAppConfig returns sane zero-value defaults used on first launch.
+func DefaultAppConfig() AppConfig {
+	return AppConfig{
+		Hotkey: "cmd+shift+a",
+		S3: S3Config{
+			PathPrefix:   "snapgo/",
+			UsePathStyle: true,
+		},
+	}
+}
+
+// IsS3Configured reports whether the user has filled the mandatory S3 fields.
+func (c AppConfig) IsS3Configured() bool {
+	return c.S3.Endpoint != "" &&
+		c.S3.Bucket != "" &&
+		c.S3.AccessKeyID != "" &&
+		c.S3.SecretAccessKey != ""
+}