DX: When restoring a site and backup path have whitespace in it, it throws an error

```
different-benches/version-15/apps took 8s
❯ bench restore ~/Documents/Site Backup/20260217_010003-my_site_ch-database.sql
Usage: bench restore [OPTIONS] SQL_FILE_PATH
Try 'bench restore --help' for help.

Error: Got unexpected extra argument (Backup/20260217_010003-my_site_ch-database.sql)

```

Start by reproducing the failure with the `bench restore` command and a SQL file path containing spaces. Trace the command's argument parsing, then verify that the complete path is accepted as one `SQL_FILE_PATH` argument and that the restore proceeds.

Written by the indexing model from the issue text.