refactor(actor): implement replica sync and ref update notification system

- Add is_write parameter to remote clients for read/write routing distinction
- Introduce RepoEntry struct with role tracking (primary/replica) for repositories
- Replace HashSet with HashMap for repository storage with role metadata
- Add ROLE_PRIMARY and ROLE_REPLICA constants for node role identification
- Implement FindPrimary and FindReplica RPC methods for role-based routing
- Add RefUpdateEvent message type for propagating reference updates
- Create sync module with BundleApplicator for handling replica synchronization
- Implement notify_ref_update calls after branch/tag/commit operations
- Add broadcast_ref_update function to propagate events across cluster nodes
- Modify route_repository to prioritize primary for writes and replicas for reads
- Update actor message handling to support role-based repository discovery
- Implement sync_from_primary function using pack protocol for incremental updates

server/archive.rs

@@ -6,12 +6,13 @@ use super::{GitksService, cache, into_status};
 async fn remote_archive_client(
     svc: &GitksService,
     header: Option<&RepositoryHeader>,
+    is_write: bool,
 ) -> Result<Option<ArchiveServiceClient<tonic::transport::Channel>>, tonic::Status> {
     let header = match header {
         Some(h) => h,
         None => return Ok(None),
     };
-    let Some(route) = svc.route_repository(header).await? else {
+    let Some(route) = svc.route_repository(header, is_write).await? else {
         return Ok(None);
     };
     tracing::info!(storage_name = %route.storage_name, relative_path = %route.relative_path, actor_name = %route.actor_name, grpc_addr = %route.grpc_addr, "forwarding archive rpc");
@@ -38,7 +39,7 @@ impl archive_service_server::ArchiveService for GitksService {
         let gb = match self.resolve(inner.repository.as_ref()) {
             Ok(gb) => gb,
             Err(err) if err.code() == tonic::Code::NotFound => {
-                if let Some(mut client) = remote_archive_client(self, inner.repository.as_ref()).await? {
+                if let Some(mut client) = remote_archive_client(self, inner.repository.as_ref(), false).await? {
                     let resp = client.get_archive(inner).await?;
                     let stream = super::bridge_server_stream(resp.into_inner());
                     return Ok(tonic::Response::new(stream));
@@ -63,7 +64,7 @@ impl archive_service_server::ArchiveService for GitksService {
         let gb = match self.resolve(inner.repository.as_ref()) {
             Ok(gb) => gb,
             Err(err) if err.code() == tonic::Code::NotFound => {
-                if let Some(mut client) = remote_archive_client(self, inner.repository.as_ref()).await? {
+                if let Some(mut client) = remote_archive_client(self, inner.repository.as_ref(), false).await? {
                     return client.list_archive_entries(inner).await;
                 }
                 return Err(err);