Adds a `db_backup` sidecar that dumps tracksolid_db every night at
02:30 UTC (configurable via BACKUP_HOUR/BACKUP_MINUTE), gzips the
output, and uploads to s3://fleet-db/daily/<dbname>_<ts>.sql.gz on
the rustfs S3-compatible instance (s3.rahamafresh.com). Prunes
objects older than BACKUP_KEEP_DAYS (default 30).
Required .env additions (Coolify UI):
RUSTFS_ENDPOINT=https://s3.rahamafresh.com
RUSTFS_ACCESS_KEY=...
RUSTFS_SECRET_KEY=...
RUSTFS_BUCKET=fleet-db
Mitigates data loss when Coolify service recreation wipes the
service-ID-scoped timescale-data volume.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
