Replaced all 36 console.log/warn/error calls in src/utilities/backup-manager.js
with log.info/log.warn/log.error from src/utils/logging. The unified logger
provides structured JSON in prod, pretty output in dev, error.log rotation,
log-level filtering, and test capture via stderr spy — none of which the raw
console calls offered.
Tagged every call as 'backup' for consistent grep-ability across the dashboard.
Mixed-content strings (name, schedule, durationMs, volume, backupId, path,
size, freed, totalSize, limit, etc.) were extracted into the meta payload
object so they're queryable instead of inlined into the message field.
1539/1539 Jest tests pass. ESLint clean for the file (10 pre-existing
warnings unchanged, zero new).