API: Undefine API_DEPRECATED to fix macos build issue

Related-to: #284
Signed-off-by: Siddharth Chandrasekaran <sidcha.dev@gmail.com>

Author: sidcha

include/osdp_export.h

@@ -48,6 +48,16 @@
 
 /* ---------- Deprecation (with message) ---------- */
 
+/*
+ * Undefine API_DEPRECATED before redefining it. On macOS the SDK header
+ * <os/availability.h> defines API_DEPRECATED with a different signature
+ * (platform/version specifiers, not a plain string), which causes macro
+ * expansion errors when osdp.h uses OSDP_DEPRECATED_EXPORT("msg").
+ */
+#ifdef API_DEPRECATED
+#undef API_DEPRECATED
+#endif
+
 /* Prefer C++ [[deprecated("msg")]] if available, otherwise compiler specifics. */
 #if defined(__cplusplus) && API_HAS_CPP_ATTR(deprecated)
   /* [[deprecated("msg")]] supported */