Remove daemon mode references and unused config fields

The --daemon flag, BackupInterval, FullScanInterval, MinTimeBetweenRun
config fields, and DirtyPath model were placeholders for a never-shipped
daemon mode and have been removed. Daemon mode is out of scope for 1.0.

internal/cli/root.go

@@ -25,7 +25,7 @@ func NewRootCommand() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "vaultik",
 		Short: "Secure incremental backup tool with asymmetric encryption",
-		Long: `vaultik is a secure incremental backup daemon that encrypts data using age
+		Long: `vaultik is a secure incremental backup tool that encrypts data using age
 public keys and uploads to S3-compatible storage. No private keys are needed
 on the source system.`,
 		SilenceUsage: true,