The store is the Writer boundary, so it computes and registers
inverses: a weak history sink bound at session composition, one
HistoryStep per gesture at exactly the brackets that were already one
performWrite each — multi-card moves, style batches, width pairs, and
multi-row restores each undo as one plurally-titled step, and the Edit
session registers once at the flip from the bytes disk held before its
first landed write, debounce ticks registering nothing. Crossings run
through performWrite, so an undo brackets the watcher, echoes through
the reload, and reaches every window; every closure captures values,
never snapshots. The inventory follows 13 exactly: moves return to
origin lane and order, renames restore or remove the title key,
restyles and resizes restore field values or absence, tombstones and
restores swap with captured timestamps, and an undone create is a real
removal — no trace — with redo re-materializing the same UUID from
bytes captured at gesture time. Purge, attachments, repair,
bookkeeping, checkbox flips, raw Apply, and the whole arrival family
register nothing, each exclusion documented where it lives. Step names
speak 06's verb vocabulary through the new HistoryPhrase.
Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY
The provider seam 12 promised: HistoryProviding speaks 13's vocabulary
— register a HistoryStep (bare 06 phrase plus undo/redo closures
returning applied or skipped), canUndo/canRedo, action names, clear —
and no UndoManager type appears anywhere in it, proven by a fake that
satisfies the seam with counters. The base provider wraps a private
UndoManager with groupsByEvent off so coalescing stays the Writer call
site's decision; undo re-registers the reversed step from inside the
undo, which makes a stale-skipped step vanish for free and the
crossing loop fall through to the next. BoardUndoManager adapts the
protocol to the responder chain — a stackless UndoManager subclass
answering from the provider — so Pro's git provider inherits menu
enablement, dynamic titles, and the nil-target toolbar pair by binding
the protocol. One stack per board session, born in beginSession,
cleared in the close flush; every window over the board answers it
through windowWillReturnUndoManager. Headless probes shaped the
routing: a real NSTextView's own manager wins natively, but a field
editor's does not — BoardUndoRouting answers the per-window text
manager while any NSText is first responder, so a search-field typo
never crosses a board step.
Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY
rzen