# Moving from Sized 1.0 to 2.0

The existing flags and table/CSV/NDJSON workflows remain. Update automation to
handle incomplete scans: exit 0 means a complete result; exit 1 means a missing
root, an incomplete scan or another operation failure. CLI argument errors use
Clap's exit 2. An incomplete scan may still produce useful output. Diagnostics
go to stderr, and each JSON report includes `complete`.

Hard-linked files now contribute allocated blocks once, owned by the first path
in deterministic traversal order. Apparent sizes remain per pathname. Totals
may be lower than 1.0 for this reason. Ignore rules inherit through directories;
`--one-file-system` explicitly skips other mounted filesystems. Allocation is
filesystem-reported blocks, not guaranteed recoverable space.

## Rust consumers

The CLI package is version 2.0.0. Its scanner is the exact `sized-core` revision
recorded in `CORE-SNAPSHOT.json`, also used by SizeQueen. The core snapshot's
internal package version remains 0.0.0; the full Git revision and file hashes
identify it. It is an included path dependency, so no private forge access or
separate core installation is required.

Public scanner types and `sized::scan` are re-exported from that dependency.
`EntryType` adds `Special` and `Unknown`; update exhaustive matches. `Node` has
additional accounting/status fields and internal state; obtain nodes through
`scan_tree` instead of struct literals. `Args` adds `one_file_system`, and
`run` returns scan completeness as a boolean. `build_tree` remains a compatibility
helper, but use `scan_tree` to retain structured errors and diagnostics.

Use a fresh `ScanControl` per scan. Cancellation is cooperative between
filesystem calls. SizeQueen does not launch the CLI; both use the core in process.