Add Docker service management

- Stop service before backup operation
- Start service after backup completion
- Proper error handling for docker-compose commands
- Dry-run support for service operations

docker2pbs.py

@@ -116,6 +116,40 @@ class Docker2PBS:
             return network_config.get('external', False)
         return False
     
+    def stop_service(self) -> None:
+        """Stop the Docker service"""
+        print(f"Stopping service: {self.service_name}")
+        cmd = ['docker-compose', '-f', str(self.compose_file), 'stop', self.service_name]
+        
+        if self.dry_run:
+            print(f"[DRY-RUN] Would run: {' '.join(cmd)}")
+            print(f"[DRY-RUN] Service {self.service_name} would be stopped")
+            return
+            
+        result = subprocess.run(cmd, capture_output=True, text=True)
+        
+        if result.returncode != 0:
+            raise RuntimeError(f"Failed to stop service: {result.stderr}")
+        
+        print(f"Service {self.service_name} stopped successfully")
+    
+    def start_service(self) -> None:
+        """Start the Docker service"""
+        print(f"Starting service: {self.service_name}")
+        cmd = ['docker-compose', '-f', str(self.compose_file), 'up', '-d', self.service_name]
+        
+        if self.dry_run:
+            print(f"[DRY-RUN] Would run: {' '.join(cmd)}")
+            print(f"[DRY-RUN] Service {self.service_name} would be started")
+            return
+            
+        result = subprocess.run(cmd, capture_output=True, text=True)
+        
+        if result.returncode != 0:
+            raise RuntimeError(f"Failed to start service: {result.stderr}")
+        
+        print(f"Service {self.service_name} started successfully")
+
 
 def main():
     parser = argparse.ArgumentParser(description='Backup Docker service to Proxmox Backup Server')