shackleton-2.0.0

chore: commit pubspec.lock for reproducible builds (#43)

The blanket *.lock ignore rule excluded pubspec.lock, so CI resolved the
latest version of every dependency on each run. That let image 4.12 land
untested and break main. Shackleton is an application, so the lockfile
should be committed; other lock files remain ignored.


Claude-Session: https://claude.ai/code/session_018kupPBz8cvscXKE2RdZ3kh

Co-authored-by: David Hobley <david.hobley@sharpblue.com.au>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>