History was limited by step count only; a whole-selection move of 50k paths keeps ~40 MB per
step. Steps now carry a size estimate (only unshared subtrees are visited) and the oldest are
dropped beyond a byte budget, keeping the last 8. Documents entering history drop their id
index, selections are shared between steps, the command journal is bounded (held while an
Action records), and document resources are copy-on-write. Saved files are byte-identical.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VmMmc1J8XeNLxhRihWv9cc