SuperLocalMemory v4.2.16

A small follow-up to 4.2.15. No new settings. One automatic data repair runs
on first start (M068, no command): it only marks machine-written session lines
so they stop being returned as answers. Nothing is deleted or edited.

Upgrade every copy of SuperLocalMemory on a machine together: once 4.2.16 has
opened a store, an older copy refuses to open it and its error lists every copy
it finds. To go back to 4.2.15, run slm db prepare-downgrade first.

Fixed

• Session-end lines with only git details no longer count as memories. The
  end-of-session summary that names just the branch and the uncommitted-file
  total ("session ended ... | branch: main | uncommitted: 2 files changed, 0
  insertions(+), 0 deletions(-)") was treated as real content, so these lines
  were returned by recall and shown at session start. They are now bookkeeping
  like the plain "session ended" line, as are the copies made from them ("the
  user's session ended ...", "The session ended on ", " is the date
  when the session ended", a bare "2 files changed, ..." line). A summary that
  lists recent commits still counts: that is what "what did I ship last
  session?" needs.
• Bookkeeping saved before the rule learned its shape is now flagged too.
  A one-time migration (M068, no command needed) checks the rows already in
  the store against every shape the rule knows, including the agent checkpoint
  and "the session ended" forms added in 4.2.14 and 4.2.15. On one real store
  it flagged 2,030 rows, every one a bare session-end time or git total.
  Nothing is deleted or edited: flagged rows stay in lists and on the
  dashboard and only leave recall answers, and a row you marked yourself is
  never touched.