Fix/doc streaming proto (#673)

* Librarian streaming doc download

* Document stream download endpoint

trustgraph-base/trustgraph/messaging/translators/library.py

@@ -174,4 +174,6 @@ class LibraryResponseTranslator(MessageTranslator):
     
     def from_response_with_completion(self, obj: LibrarianResponse) -> Tuple[Dict[str, Any], bool]:
         """Returns (response_dict, is_final)"""
-        return self.from_pulsar(obj), True
+        # For streaming responses, check end_of_stream to determine if this is the final message
+        is_final = getattr(obj, 'end_of_stream', True)
+        return self.from_pulsar(obj), is_final

trustgraph-base/trustgraph/schema/services/library.py

@@ -212,6 +212,9 @@ class LibrarianResponse:
     # list-uploads response
     upload_sessions: list[UploadSession] = field(default_factory=list)
 
+    # stream-document response - indicates final chunk in stream
+    end_of_stream: bool = False
+
 # FIXME: Is this right?  Using persistence on librarian so that
 # message chunking works