fix(memory): set updated_at on creation and preserve pre-existing created_at (#4499)

Co-authored-by: utkarsh240799 <utkarsh240799@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mem0/memory/main.py

@@ -1200,7 +1200,9 @@ class Memory(MemoryBase):
         new_metadata = deepcopy(metadata) if metadata is not None else {}
         new_metadata["data"] = data
         new_metadata["hash"] = hashlib.md5(data.encode()).hexdigest()
-        new_metadata["created_at"] = datetime.now(timezone.utc).isoformat()
+        if "created_at" not in new_metadata:
+            new_metadata["created_at"] = datetime.now(timezone.utc).isoformat()
+        new_metadata["updated_at"] = new_metadata["created_at"]
 
         self.vector_store.insert(
             vectors=[embeddings],
@@ -1213,6 +1215,7 @@ class Memory(MemoryBase):
             data,
             "ADD",
             created_at=new_metadata.get("created_at"),
+            updated_at=new_metadata.get("updated_at"),
             actor_id=new_metadata.get("actor_id"),
             role=new_metadata.get("role"),
         )
@@ -2329,7 +2332,9 @@ class AsyncMemory(MemoryBase):
         new_metadata = deepcopy(metadata) if metadata is not None else {}
         new_metadata["data"] = data
         new_metadata["hash"] = hashlib.md5(data.encode()).hexdigest()
-        new_metadata["created_at"] = datetime.now(timezone.utc).isoformat()
+        if "created_at" not in new_metadata:
+            new_metadata["created_at"] = datetime.now(timezone.utc).isoformat()
+        new_metadata["updated_at"] = new_metadata["created_at"]
 
         await asyncio.to_thread(
             self.vector_store.insert,
@@ -2345,6 +2350,7 @@ class AsyncMemory(MemoryBase):
             data,
             "ADD",
             created_at=new_metadata.get("created_at"),
+            updated_at=new_metadata.get("updated_at"),
             actor_id=new_metadata.get("actor_id"),
             role=new_metadata.get("role"),
         )