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/cursor/cursor.go

@@ -0,0 +1,12 @@
+// Package cursor exposes the current mouse pointer position in a
+// platform-agnostic way. We use it to anchor the post-capture toolbar near
+// the location where the user released the mouse — on macOS that point is
+// effectively the bottom-right corner of the screencapture selection.
+package cursor
+
+// Point is a screen-space pointer location, in *logical* pixels (i.e. the
+// coordinate system Wails uses for window placement).
+type Point struct {
+	X int
+	Y int
+}

internal/infrastructure/cursor/cursor_darwin.go

@@ -0,0 +1,30 @@
+//go:build darwin
+
+// cursor_darwin.go reads the global cursor position via Quartz Event
+// Services. This API is preferable to NSEvent.mouseLocation for our use
+// case because it returns the pointer in flipped (top-left origin)
+// coordinates, which matches Wails / web pixel coordinates exactly.
+package cursor
+
+/*
+#cgo LDFLAGS: -framework ApplicationServices
+#include <ApplicationServices/ApplicationServices.h>
+
+// readCursor returns the current mouse position with origin at the
+// top-left of the primary display, in logical pixels.
+static void readCursor(double* x, double* y) {
+    CGEventRef event = CGEventCreate(NULL);
+    CGPoint p = CGEventGetLocation(event);
+    if (event) CFRelease(event);
+    *x = p.x;
+    *y = p.y;
+}
+*/
+import "C"
+
+// Get returns the current mouse pointer position.
+func Get() (Point, error) {
+	var x, y C.double
+	C.readCursor(&x, &y)
+	return Point{X: int(x), Y: int(y)}, nil
+}

internal/infrastructure/cursor/cursor_other.go

@@ -0,0 +1,9 @@
+//go:build !darwin
+
+package cursor
+
+// Get is a no-op stub on non-macOS targets. The toolbar will fall back to
+// the centre of the screen on these platforms.
+func Get() (Point, error) {
+	return Point{X: 0, Y: 0}, nil
+}