Implement robust logging with flexi_logger and update CI to verify logs

src/commands.rs

@@ -1222,6 +1222,8 @@ async fn cmd_attack(pid: usize, target: &str, state: &SharedState) -> CommandRes
         });
     }
 
+    log::info!(target: "{combat}", "Combat: Player '{}' (ID {}) engaged NPC '{}' ({}) in combat", pname, pid, npc_name, npc_id);
+
     CommandResult {
         output: format!(
             "{}\r\n{}\r\n{}",