test(v9): keyboard shortcut surface sweep (nightly, SHORTCUT_SWEEP=1)

Presses every shortcut a user is likely to hit -- 83 word / 125 cell /
107 slide -- as trusted page.keyboard input into each editor, checks
fatal dialog / asc_onError / stuck long-action / loaded state after each
one (dismissing whatever dialog it opened), and proves the document
still saves afterwards. First run is green on all three editors; the
only record is cell Cmd+Shift+L (toggle filter with no data range)
raising an informational asc_onError. Ledger section D updated.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: chaxus