Consolidate log viewing to use service-manage logs action

Replace separate service_logs_cmd with service-manage logs action
to unify service management through single script interface.
Dashboard now calls 'service-manage logs <service>' which provides
intelligent log viewing based on service state and configuration.

dashboard/src/config/mod.rs

@@ -57,7 +57,6 @@ pub struct SshConfig {
     pub rebuild_user: String,
     pub rebuild_cmd: String,
     pub service_manage_cmd: String,
-    pub service_logs_cmd: String,
 }
 
 /// Service log file configuration per host