refactor: consolidate service commands into modular structure with complete logic

Replace individual service command initialization with unified InitServiceCmd()
that creates a complete service command hierarchy. Port all original logic
from initStartCmd, initStopCmd, initRestartCmd, initReloadCmd, initStatusCmd,
and initUninstallCmd into ServiceCommand methods with proper dependency injection.

Key changes:
- Port complete Start logic including config validation, service installation,
  DNS management, and self-check functionality
- Port complete Stop logic with deactivation pin validation and DNS cleanup
- Port complete Restart logic with config validation and DNS restoration
- Port complete Reload logic with HTTP status handling and restart fallback
- Port complete Status logic with proper exit codes
- Port complete Uninstall logic with cleanup file removal
- Add all necessary flags to service commands (iface, pin, etc.)
- Use InitInterfacesCmd() for interfaces subcommand
- Simplify cli.go by replacing multiple init calls with single InitServiceCmd()

This refactoring eliminates code duplication, improves maintainability, and
ensures all service commands have their complete original functionality.

cmd/cli/cli.go

@@ -128,14 +128,7 @@ func initCLI() {
 	rootCmd.CompletionOptions.HiddenDefaultCmd = true
 
 	initRunCmd()
-	startCmd := initStartCmd()
-	stopCmd := initStopCmd()
-	restartCmd := initRestartCmd()
-	reloadCmd := initReloadCmd(restartCmd)
-	statusCmd := initStatusCmd()
-	uninstallCmd := initUninstallCmd()
-	interfacesCmd := initInterfacesCmd()
-	initServicesCmd(startCmd, stopCmd, restartCmd, reloadCmd, statusCmd, uninstallCmd, interfacesCmd)
+	InitServiceCmd()
 	initClientsCmd()
 	initUpgradeCmd()
 	InitLogCmd()