Adds auto-detection of pre-existing Samba shares and NFS exports when
nasctl is installed on a host that already has these configs.
New package internal/importer parses smb.conf (INI-style) and
/etc/exports (line-based) and imports them into SQLite.
Imported shares/exports are marked dirty so the user must review
and apply manually before any file is overwritten.
Backup: before the first Apply, each module backs up the original
config to <path>.nasctl.bak.<timestamp> (one time only).
New CLI flag --import-on-boot / NASCTL_IMPORT_ON_BOOT env var
(default false, opt-in).
New API endpoints:
GET /api/import/status
POST /api/import/samba
POST /api/import/nfs
New DB methods ReplaceSambaShares/ReplaceNFSExports (transactional
replace-all), guarded by import.samba.done / import.nfs.done
settings flags.