test: add normalization test for bridge-IP subnet form (atlas note)

hive-c0re/src/lifecycle.rs

@@ -1377,6 +1377,21 @@ mod tests {
         assert!(agent_network_ip("alice", "10.0.0.0").is_none());    // no prefix
     }
 
+    #[test]
+    fn agent_network_ip_normalizes_bridge_ip_subnet() {
+        // HIVE_NETWORK_SUBNET carries the bridge IP (10.42.0.1/24), not
+        // canonical network (10.42.0.0/24). Both must produce the same result
+        // after host-bit masking.
+        let from_bridge = agent_network_ip("alice", "10.42.0.1/24");
+        let from_canonical = agent_network_ip("alice", "10.42.0.0/24");
+        assert_eq!(from_bridge, from_canonical,
+            "bridge-IP and canonical-network form should normalize to the same result");
+        // Result must still be in .2-.254.
+        let ip = from_bridge.unwrap();
+        let last: u8 = ip.rsplit('.').next().unwrap().parse().unwrap();
+        assert!(last >= 2 && last <= 254, "host byte {last}");
+    }
+
     /// `setup_proposed` is idempotent: calling it on an existing repo is a
     /// no-op (the fresh guard skips all writes).
     #[tokio::test]