Update /ok to serve dual health check/benchmarking role

src/pipeline_entry.hpp

@@ -32,6 +32,19 @@ struct StatusEntry {
       : connection(std::move(conn)) {}
 };
 
+/**
+ * Pipeline entry for /ok health check requests.
+ * Flows through all pipeline stages as a noop except resolve stage.
+ * Resolve stage can perform configurable CPU work for benchmarking.
+ */
+struct HealthCheckEntry {
+  std::unique_ptr<Connection> connection;
+
+  HealthCheckEntry() = default; // Default constructor for variant
+  explicit HealthCheckEntry(std::unique_ptr<Connection> conn)
+      : connection(std::move(conn)) {}
+};
+
 /**
  * Pipeline entry for coordinated shutdown of all stages.
  * Flows through all stages to ensure proper cleanup.
@@ -44,4 +57,5 @@ struct ShutdownEntry {
  * Pipeline entry variant type used by the commit processing pipeline.
  * Each stage pattern-matches on the variant type to handle appropriately.
  */
-using PipelineEntry = std::variant<CommitEntry, StatusEntry, ShutdownEntry>;
+using PipelineEntry =
+    std::variant<CommitEntry, StatusEntry, HealthCheckEntry, ShutdownEntry>;