fix(mail-overview): don't re-notify the prior batch, flatten newlines

The lastmod range is inclusive at both ends and the stored revision
was reused as the next start, so the batch just notified matched
again. Start one revision later.

A subject can contain a newline, which broke the bullet rows and the
+N more count; flatten CR/LF to a space before escaping.

Also reconciles the state-write comment and spec with the actual
skip-and-advance failure behavior, and corrects two doc wordings.

0 files changed, 0 insertions, 0 deletions