Tab used to fall through to the browser's focus navigation everywhere.
Inside tables it now moves cell-wise (Shift-Tab backwards) and appends a
new row from the last cell, Word-style. Outside tables every branch
returns false, so Tab keeps leaving the editor.
Capturing Tab inside tables needs a documented way out (WCAG 2.1.2):
Escape places the cursor after the table -- unlike the arrow keys, which
reach the gap cursor (#335) only from the table's edge cells, it works
from every cell, including from a cell selection. When no textblock
follows the table it falls back to the gap cursor position. The
mechanism is announced to assistive tech via an aria-describedby hint
on the editor surface (visually hidden, de+en).
e2e: cell round trip per Tab/Shift-Tab with typed markers, row append
from the last cell, and the full keyboard-only exit (Escape, then Tab
leaves the editor). The table specs now settle briefly after the insert
-- right after it the collab sync can swallow a click's selection
update, which had the markers landing in stale selections.
Closes#338
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012aoPvnakfBP28nAfijgUY9