Rewrite home_assistant_backup.sh as a single Go binary that reads the
existing home_assistant_backup.conf unchanged.
- Create a backup over SSH, scp it locally, and prune old backups both
on the HA host (when free space is low) and locally
- Send ntfy and Discord notifications at the same points as the script
- Drop the jq and yq dependencies: parse `ha backups --raw-json` and
`ha backup new --raw-json` in Go, falling back to `slug:` line parsing
- Add timestamped progress output, a heartbeat while HA builds the
backup, and live size/percent/speed reporting during the copy
- Build the Discord payload with json.Marshal and validate backup slugs
before using them in remote commands
- Abort with a notification if the remote disk-space check fails
- Add -config and -version flags
- Build with CGO_ENABLED=0 for a static binary that runs on older glibc
phil