🆕 Add window size persistence, exit codes, and screen size detection

screen_darwin.go

@@ -0,0 +1,32 @@
+//go:build darwin
+
+package main
+
+import (
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+// desktopSize returns the visible desktop size in points (device-independent
+// pixels), matching Fyne's coordinate system. It uses osascript instead of
+// cgo so the binary stays a plain Go build. Returns (0, 0) if it can't be
+// determined, in which case the caller skips clamping.
+func desktopSize() (float32, float32) {
+	// "bounds of window of desktop" -> "0, 0, W, H" in points.
+	out, err := exec.Command("osascript", "-e",
+		`tell application "Finder" to get bounds of window of desktop`).Output()
+	if err != nil {
+		return 0, 0
+	}
+	parts := strings.Split(strings.TrimSpace(string(out)), ", ")
+	if len(parts) < 4 {
+		return 0, 0
+	}
+	w, errW := strconv.ParseFloat(strings.TrimSpace(parts[2]), 32)
+	h, errH := strconv.ParseFloat(strings.TrimSpace(parts[3]), 32)
+	if errW != nil || errH != nil {
+		return 0, 0
+	}
+	return float32(w), float32(h)
+}