fix(topic): separate topic memo from transaction memo

Signed-off-by: iron-prog <dt915725@gmail.com>

Author: iron-prog

src/hiero_sdk_python/consensus/topic_create_transaction.py

@@ -63,7 +63,7 @@ def __init__(
             fee_exempt_keys (list[Key], optional): Optional list of fee exempt keys for the topic (PrivateKey or PublicKey).
         """
         super().__init__()
-        self.memo: str = memo or ""
+        self.topic_memo: str = memo or ""
         self.admin_key: Key | None = admin_key
         self.submit_key: Key | None = submit_key
         self.auto_renew_period: Duration = auto_renew_period or Duration(7890000)
@@ -84,7 +84,7 @@ def set_memo(self, memo: str) -> TopicCreateTransaction:
             TopicCreateTransaction: The current instance for method chaining.
         """
         self._require_not_frozen()
-        self.memo = memo
+        self.topic_memo = memo
         return self
 
     def set_admin_key(self, key: Key) -> TopicCreateTransaction:
@@ -237,7 +237,7 @@ def _build_proto_body(self) -> consensus_create_topic_pb2.ConsensusCreateTopicTr
             submitKey=key_to_proto(self.submit_key),
             autoRenewPeriod=(self.auto_renew_period._to_proto() if self.auto_renew_period is not None else None),
             autoRenewAccount=(self.auto_renew_account._to_proto() if self.auto_renew_account is not None else None),
-            memo=self.memo,
+            memo=self.topic_memo,
             custom_fees=[custom_fee._to_topic_fee_proto() for custom_fee in self.custom_fees],
             fee_schedule_key=key_to_proto(self.fee_schedule_key),
             fee_exempt_key_list=[key_to_proto(key) for key in self.fee_exempt_keys],

src/hiero_sdk_python/consensus/topic_update_transaction.py

@@ -57,7 +57,7 @@ def __init__(
         """
         super().__init__()
         self.topic_id: TopicId | None = topic_id
-        self.memo: str = memo or ""
+        self.topic_memo: str = memo or ""
         self.admin_key: Key | None = admin_key
         self.submit_key: Key | None = submit_key
         self.auto_renew_period: Duration | None = auto_renew_period
@@ -93,7 +93,7 @@ def set_memo(self, memo: str) -> TopicUpdateTransaction:
             TopicUpdateTransaction: Returns the instance for method chaining.
         """
         self._require_not_frozen()
-        self.memo = memo
+        self.topic_memo = memo
         return self
 
     def set_admin_key(self, key: Key) -> TopicUpdateTransaction:
@@ -271,7 +271,7 @@ def _build_proto_body(self) -> consensus_update_topic_pb2.ConsensusUpdateTopicTr
             ),
             autoRenewAccount=(self.auto_renew_account._to_proto() if self.auto_renew_account else None),
             expirationTime=self.expiration_time._to_protobuf() if self.expiration_time else None,
-            memo=_wrappers_pb2.StringValue(value=self.memo) if self.memo is not None else None,
+            memo=_wrappers_pb2.StringValue(value=self.topic_memo) if self.topic_memo is not None else None,
             custom_fees=custom_fees,
             fee_schedule_key=key_to_proto(self.fee_schedule_key) if self.fee_schedule_key else None,
             fee_exempt_key_list=fee_exempt_key_list,