refactor(cluster): use compile-time assertions for wire version invariants

Replace the two unit tests in wire_version.rs with const assertions that
are evaluated at compile time, so violations fail the build rather than a
test run. Also reorder a pair of pub use items in nodedb-cluster to match
the module declaration order, and collapse a multi-line format string in
the RPC codec header error to a single line.

Author: farhan-syah

nodedb-cluster/src/lib.rs

@@ -58,12 +58,12 @@ pub use bootstrap::{
     ClusterConfig, ClusterState, JoinRetryPolicy, start_cluster, start_cluster_subsystems,
 };
 pub use catalog::ClusterCatalog;
+pub use circuit_breaker::BreakerSnapshot;
+pub use closed_timestamp::ClosedTimestampTracker;
 pub use cluster_epoch::{
     bump_local_cluster_epoch, current_local_cluster_epoch, init_local_cluster_epoch_from_catalog,
     observe_peer_cluster_epoch, set_local_cluster_epoch,
 };
-pub use circuit_breaker::BreakerSnapshot;
-pub use closed_timestamp::ClosedTimestampTracker;
 pub use cluster_info::{
     ClusterInfoSnapshot, ClusterObserver, GroupSnapshot, GroupStatusProvider, PeerSnapshot,
 };

nodedb-cluster/src/rpc_codec/header.rs

@@ -94,9 +94,7 @@ pub fn write_frame(rpc_type: u8, payload: &[u8], out: &mut Vec<u8>) -> Result<()
 pub fn parse_frame(data: &[u8]) -> Result<(u8, &[u8])> {
     if data.is_empty() {
         return Err(ClusterError::Codec {
-            detail: format!(
-                "frame too short: 0 bytes, need {HEADER_SIZE_V2}"
-            ),
+            detail: format!("frame too short: 0 bytes, need {HEADER_SIZE_V2}"),
         });
     }
 

nodedb-types/src/wire_version.rs

@@ -21,19 +21,8 @@ pub const WIRE_FORMAT_VERSION: u16 = 4;
 /// below this are rejected.
 pub const MIN_WIRE_FORMAT_VERSION: u16 = 1;
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn min_does_not_exceed_current() {
-        assert!(MIN_WIRE_FORMAT_VERSION <= WIRE_FORMAT_VERSION);
-    }
-
-    #[test]
-    fn current_is_nonzero() {
-        // Version 0 is reserved for "unknown / legacy" handling on
-        // downstream paths and must never be the active version.
-        assert!(WIRE_FORMAT_VERSION > 0);
-    }
-}
+// Compile-time invariants — these constants must satisfy:
+//   - MIN_WIRE_FORMAT_VERSION <= WIRE_FORMAT_VERSION
+//   - WIRE_FORMAT_VERSION > 0  (version 0 is reserved for "unknown/legacy")
+const _: () = assert!(MIN_WIRE_FORMAT_VERSION <= WIRE_FORMAT_VERSION);
+const _: () = assert!(WIRE_FORMAT_VERSION > 0);