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/screencapture/capturer_other.go

@@ -0,0 +1,71 @@
+//go:build !darwin
+
+package screencapture
+
+import (
+	"bytes"
+	"fmt"
+	"image"
+	"image/png"
+
+	"github.com/kbinani/screenshot"
+)
+
+// kbinaniCapturer is the default non-darwin Capturer.
+type kbinaniCapturer struct{}
+
+// New returns the default cross-platform Capturer for non-macOS systems.
+func New() Capturer { return &kbinaniCapturer{} }
+
+func (c *kbinaniCapturer) VirtualBounds() image.Rectangle {
+	n := screenshot.NumActiveDisplays()
+	if n == 0 {
+		return image.Rect(0, 0, 0, 0)
+	}
+	bounds := screenshot.GetDisplayBounds(0)
+	for i := 1; i < n; i++ {
+		bounds = bounds.Union(screenshot.GetDisplayBounds(i))
+	}
+	return bounds
+}
+
+func (c *kbinaniCapturer) CaptureRegion(rect image.Rectangle) ([]byte, error) {
+	if rect.Dx() <= 0 || rect.Dy() <= 0 {
+		return nil, fmt.Errorf("invalid capture rectangle: %v", rect)
+	}
+	img, err := screenshot.CaptureRect(rect)
+	if err != nil {
+		return nil, fmt.Errorf("capture: %w", err)
+	}
+	var buf bytes.Buffer
+	if err := png.Encode(&buf, img); err != nil {
+		return nil, fmt.Errorf("encode png: %w", err)
+	}
+	return buf.Bytes(), nil
+}
+
+// CaptureInteractive on non-darwin platforms is not yet implemented. The
+// frontend overlay still works there. We surface a clear error so callers
+// can decide whether to fall back to the WebView overlay.
+func (c *kbinaniCapturer) CaptureInteractive() ([]byte, error) {
+	return nil, fmt.Errorf("interactive capture is not implemented on this platform yet")
+}
+
+// CaptureFullScreen grabs the primary display via kbinani/screenshot and
+// PNG-encodes the result. Multi-display extension is deliberately deferred
+// to keep parity with the macOS "primary only" UX.
+func (c *kbinaniCapturer) CaptureFullScreen() ([]byte, error) {
+	if screenshot.NumActiveDisplays() == 0 {
+		return nil, fmt.Errorf("no active display detected")
+	}
+	bounds := screenshot.GetDisplayBounds(0)
+	img, err := screenshot.CaptureRect(bounds)
+	if err != nil {
+		return nil, fmt.Errorf("capture full screen: %w", err)
+	}
+	var buf bytes.Buffer
+	if err := png.Encode(&buf, img); err != nil {
+		return nil, fmt.Errorf("encode png: %w", err)
+	}
+	return buf.Bytes(), nil
+}