Add TransportWorker and enhance logging: Introduced TransportWorker to the worker module and improved shutdown logging in the daemon for better visibility during system termination. Updated watchdog thread sleep mechanism for quicker shutdown response and refined error handling in DbError conversion to include SQLSTATE as a string.

src/worker/base.rs

@@ -95,10 +95,14 @@ impl BaseWorker {
 
         self.watchdog_thread = Some(thread::spawn(move || {
             while state.running_watchdog.load(Ordering::Relaxed) {
-                thread::sleep(Duration::from_secs(10));
-
-                if !state.running_watchdog.load(Ordering::Relaxed) {
-                    break;
+                // Nicht in einem großen 10s-Sleep blockieren, damit der
+                // Shutdown (stop_watchdog) zügig reagieren kann. Stattdessen
+                // in 1s-Scheiben schlafen und dazwischen das Flag prüfen.
+                for _ in 0..10 {
+                    if !state.running_watchdog.load(Ordering::Relaxed) {
+                        break;
+                    }
+                    thread::sleep(Duration::from_secs(1));
                 }
 
                 let step = state.current_step.lock().unwrap().clone();