chore(server): add reasons to expect attributes

crates/server/src/save/region_actor.rs

@@ -47,8 +47,10 @@ pub struct SaveActor {
     /// The sending end of the request channel; cloned into every worker so it can issue reads.
     request_tx: Sender<SaveRequest>,
     /// The actor thread handle, retained so it can be joined on shutdown.
-    // * Retained ahead of a dedicated shutdown path; not yet read because the server has no graceful-stop sequence.
-    #[expect(dead_code)]
+    #[expect(
+        dead_code,
+        reason = "retained for a future graceful-shutdown join path"
+    )]
     handle: JoinHandle<()>,
 }
 

crates/server/src/world_server.rs

@@ -46,13 +46,17 @@ pub struct ServerWorld {
     /// Positions dispatched to a worker but not yet returned, preventing the same chunk being re-dispatched on subsequent passes.
     in_flight: HashSet<ChunkPos>,
     /// The dedicated thread owning all region files, kept alive for the world's lifetime.
-    // Retained so its request channel stays open for the workers; not read again after construction.
-    #[expect(dead_code)]
+    #[expect(
+        dead_code,
+        reason = "retained to keep the save request channel open for the workers"
+    )]
     save_actor: SaveActor,
     /// Handles to the generation worker threads, retained so they can be joined on shutdown.
-    // * NOTE: Retained ahead of a dedicated shutdown path
     // TODO: Remove once the server has a graceful-stop sequence
-    #[expect(dead_code)]
+    #[expect(
+        dead_code,
+        reason = "retained for a future graceful-shutdown join path"
+    )]
     workers: Vec<JoinHandle<()>>,
     /// The same read-only generator handle the workers share, held so eviction can regenerate a chunk's baseline to diff against.
     generator: Arc<VoxelGenerator>,