fix: declare cr in terminfo -- another real capability missing by omission
cr (carriage return) was simply never declared, with no comment
suggesting it was deliberate (unlike bce's history) -- feed_ground's
bare '\r' handling (vt/parser.odin) has always correctly reset
cursor_x to 0.
Same shape of consequence as the bce gap: an ncurses-linked TUI's
cursor-movement optimizer won't reach for "\r" without seeing cr
declared, and can fall back to a cursor-down move alone (cud) to
reach a target row -- which, correctly, never touches the column,
landing a redraw at whatever column the cursor already happened to be
on. Root-caused via a real nvim session: switching modes wrote the
mode indicator (NORMAL/VISUAL/COMMAND) at the edit cursor's column
instead of the statusline's left edge, garbling whatever text was
already there -- reproduced byte-for-byte by replaying the exact
capture into a real tmux pane.
Adds a bce-style behavior-linking test (see the commit that added
that pattern) rather than a second independent capability list entry.