add flutter

test/database.rules.merge-only.txt

@@ -0,0 +1,23 @@
+# Add this block inside "rules" only (do not replace your existing rules)
+# Firebase project is shared with other apps — merge, don't replace.
+
+"merchant_messages": {
+  "$uid": {
+    ".read": "auth != null",
+    ".write": "auth != null"
+  }
+}
+
+# Example if you already have other paths (customer, driver, etc.):
+# {
+#   "rules": {
+#     "customer_messages": { ... },
+#     "driver_messages": { ... },
+#     "merchant_messages": {
+#       "$uid": {
+#         ".read": "auth != null",
+#         ".write": "auth != null"
+#       }
+#     }
+#   }
+# }