fixed bug with adding a single embedding

Author: bigabig

backend/src/app/core/vector/crud/crud_base.py

@@ -97,12 +97,20 @@ def add_embedding(
             embedding: Vector embedding
         """
         collection = self._get_collection(client=client, project_id=project_id)
-        collection.data.replace(
-            uuid=id.uuidv5(),
-            properties=id.model_dump(),
-            references=None,
-            vector=embedding,
-        )
+        if collection.data.exists(uuid=id.uuidv5()):
+            collection.data.replace(
+                uuid=id.uuidv5(),
+                properties=id.model_dump(),
+                references=None,
+                vector=embedding,
+            )
+        else:
+            collection.data.insert(
+                uuid=id.uuidv5(),
+                properties=id.model_dump(),
+                references=None,
+                vector=embedding,
+            )
 
     def add_embedding_batch(
         self,