Limit snapshot storage scans recorded by backup workers so very large backup targets cannot make run finalization walk unbounded file trees. Limited scans now record scan_limited, entries_scanned, and max_entries in snapshot storage metadata.
Closes#100
Parse rsync --stats output into structured run metrics for file counts,
transferred bytes, literal data, matched data, speedup, and estimated
link-dest savings.
Store collected stats on backup run results and successful snapshot metadata,
including snapshot data usage and backup-root capacity details for future
dashboard graphs and disk-full projections.
Render the collected metrics on run and snapshot detail pages, with tests
covering parsing, metadata persistence, and UI output.