Start a living doc of expected text editor behaviors. First entry: Enter
on a blank list item outdents one level, and at the top level converts the
item to a normal non-list block while preserving its text type (heading,
blockquote, or plain text).

https://claude.ai/code/session_01V4wW9QQpVzduvU5K3BzNGq

Conflict in components/Blocks/TextBlock/keymap.ts: main moved undo grouping
into the enter command (um.startGroup / asyncRun().finally(endGroup)); kept
that alongside this branch's focus-retry that waits for the new block's editor
to register instead of a fixed 10ms timeout. addBlock list-atomicity and
outdentBlock validate-before-retract auto-merged cleanly.

https://claude.ai/code/session_01V4wW9QQpVzduvU5K3BzNGq

Conflict in keymap.ts focus handling: main's "handle focus on redo" extracted
focusNewBlock and added an undo-redo handler to move the cursor into the new
block on redo. Kept main's redo handling and .finally(endGroup) placement, and
folded this branch's retry-until-the-editor-registers into focusNewBlock so
both the normal and redo focus paths are resilient to the mount race.

https://claude.ai/code/session_01V4wW9QQpVzduvU5K3BzNGq

indent fired retractFact + addLastBlock without awaiting them. main's undo
refactor closes the undo group when the command promise settles (replacing the
old 100ms endGroup timeout), so the un-awaited mutators registered their undo
ops after the group closed — as two separate entries. One undo then reversed
only addLastBlock (retracting the new card/block fact) and orphaned the block;
a second undo restored it.

Await both mutations (as outdent already does) so their undo ops land inside
the group and a single undo restores the block to its prior position.

https://claude.ai/code/session_01V4wW9QQpVzduvU5K3BzNGq

Three independent defects surfaced by the subagent investigation:

- retractFact's redo closure omitted ignoreUndo, so redoing any indent/outdent
  re-entered the undo manager — truncating the redo stack and pushing a dangling
  entry that double-referenced then lost the block. Add ignoreUndo (every other
  closure already passes it).

- indent did retract-old-fact + add-new-factID. A mis-grouped undo could apply
  only the add and orphan the block. Reparent the existing card/block fact in a
  single mutation (reuse its factID) so it's one symmetric undo entry that can't
  be half-applied.

- the nested sibling sort in getBlocks had no id tiebreak (the top-level sorts
  do), so equal/colliding positions rendered in unstable order. Add the tiebreak.

https://claude.ai/code/session_01V4wW9QQpVzduvU5K3BzNGq

addGrouped coalesced every text edit within the 200ms window regardless of
source, so edits to two different blocks within the window merged into one undo
step (only the blur flush saved it). Take a span key (the block/footnote
entityID): consecutive same-key edits coalesce within the window, and a
different key finalizes the open group immediately so distinct spans never
merge — independent of timing or blur. trackUndoRedo threads the editor's
entityID through as the key.

https://claude.ai/code/session_01V4wW9QQpVzduvU5K3BzNGq

Text-edit coalescing was correct, but the group got finalized between
keystrokes, so each character became its own undo step:

- The <pre> onBlur handler called undoManager.flushGroup() on every blur, and
  focus churn during the deferred-updateState re-render fired it mid-run.
  Remove the blur flush (and the now-unused flushGroup); the idle timer, command
  groups, span-key changes, and undo/redo already provide every real boundary.
- COALESCE_MS was 200ms — shorter than a normal inter-keystroke gap (typing
  below ~5 cps), so the timer flushed between keystrokes. Raise to 500ms; the
  timer resets each keystroke, so a run now coalesces until an actual pause.

https://claude.ai/code/session_01V4wW9QQpVzduvU5K3BzNGq