Fix interactive prompt: keep reverse-video escape inside readline markers
The colored prompt brackets its ANSI escapes with RL_PROMPT_START_IGNORE
(\001) and RL_PROMPT_END_IGNORE (\002) so readline does not count them toward
the prompt width. In the reverse-video opener, \002 was placed before the
terminating 'm' of \x1b[7m, leaving 'm' outside the ignore region. readline
counted it as a visible column, making the prompt one column wider than it
renders. That off-by-one shifted readline's input-start position, so Backspace
could not delete the first typed character.
Move \002 to after the 'm' so the whole \x1b[7m sits inside the markers. This
fixes both PROMPTMSG (reverse-video prompt) and the per-DB prompt suffix.
