Implement initial CLI command for narratio restore, and extract shared helper functions from the run stages

internal/app/commands.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 )
 
-var supportedCommands = []string{"run", "plan", "status", "resume", "run-stage"}
+var supportedCommands = []string{"run", "plan", "status", "resume", "run-stage", "restore"}
 
 // Execute dispatches CLI commands and returns a process exit code.
 func Execute(args []string, stdout, stderr io.Writer) int {
@@ -32,6 +32,8 @@ func Execute(args []string, stdout, stderr io.Writer) int {
 		err = Resume(ctx, cmdArgs, stdout)
 	case "run-stage":
 		err = RunStage(ctx, cmdArgs, stdout)
+	case "restore":
+		err = Restore(ctx, cmdArgs, stdout)
 	default:
 		fmt.Fprintf(stderr, "unknown command: %q\n\n", cmd)
 		printUsage(stderr)