Undoing a consolidate concluded its moved entries a second time, and a later
removal deleted only the newer conclusion. An undo's added entry is now
concluded only when the ledger decided a Conclude for it and then an
Unconclude: an entry still concluded, or never concluded (a secret session's,
one from before sync), gets nothing. Ledger::concluded and unconcluded answer
from the decisions, in a module of their own to keep ledger.rs under 500 lines.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
