Multi platform support

server/internal/service/platform_http.go

@@ -0,0 +1,24 @@
+package service
+
+import (
+	"net/http"
+	"strings"
+)
+
+const (
+	platformAndroid = "android"
+	platformIOS     = "ios"
+)
+
+// platformFromUserAgent classifies an HTTP request as iOS vs Android based on
+// the User-Agent header. Unity's UnityWebRequest does not set a UA on iOS, so
+// CFNetwork's default ("<bundle>/<build> CFNetwork/x Darwin/x") is what arrives;
+// on Android Unity sets "UnityPlayer/... (UnityWebRequest/...)". Any other UA
+// (or none) is treated as Android, matching model.DefaultPlatform.
+func platformFromUserAgent(r *http.Request) string {
+	ua := r.Header.Get("User-Agent")
+	if strings.Contains(ua, "Darwin/") || strings.Contains(ua, "CFNetwork/") {
+		return platformIOS
+	}
+	return platformAndroid
+}