fix: Duplicate contacts creating for Argentina numbers (#11173)

app/services/whatsapp/phone_normalizers/argentina_phone_normalizer.rb

@@ -0,0 +1,18 @@
+# Handles Argentina phone number normalization
+#
+# Argentina phone numbers can appear with or without "9" after country code
+# This normalizer removes the "9" when present to create consistent format: 54 + area + number
+class Whatsapp::PhoneNormalizers::ArgentinaPhoneNormalizer < Whatsapp::PhoneNormalizers::BasePhoneNormalizer
+  def normalize(waid)
+    return waid unless handles_country?(waid)
+
+    # Remove "9" after country code if present (549 → 54)
+    waid.sub(/^549/, '54')
+  end
+
+  private
+
+  def country_code_pattern
+    /^54/
+  end
+end