refactor(actor): implement Raft consensus algorithm for cluster leader election

- Add voting mechanism with term tracking and vote persistence
- Implement election triggering logic with majority vote counting
- Add primary/replica role transition handling with state management
- Integrate health check failure detection for automatic elections
- Refactor actor messaging system for distributed coordination
- Update repository registration to query cluster for existing primary
- Add broadcast mechanism for role change notifications
- Implement proper term comparison and duplicate request filtering
- Upgrade dependency versions including tokio-util for async utilities
- Optimize code formatting and line wrapping for improved readability
- Remove redundant blank lines and improve code structure consistency
- Enhance error logging and trace information for debugging purposes

server/diff.rs

@@ -170,9 +170,10 @@ impl diff_service_server::DiffService for GitksService {
         Ok(tonic::Response::new(resp))
     }
 
-
-    type RawDiffStream = tokio_stream::wrappers::ReceiverStream<Result<RawDiffResponse, tonic::Status>>;
-    type RawPatchStream = tokio_stream::wrappers::ReceiverStream<Result<RawPatchResponse, tonic::Status>>;
+    type RawDiffStream =
+        tokio_stream::wrappers::ReceiverStream<Result<RawDiffResponse, tonic::Status>>;
+    type RawPatchStream =
+        tokio_stream::wrappers::ReceiverStream<Result<RawPatchResponse, tonic::Status>>;
 
     async fn raw_diff(
         &self,
@@ -200,7 +201,6 @@ impl diff_service_server::DiffService for GitksService {
         Ok(tonic::Response::new(into_stream(chunks)))
     }
 
-
     async fn find_changed_paths(
         &self,
         request: tonic::Request<FindChangedPathsRequest>,