Latch v0.5.2.0 — hot-path SQL

Fewer SQLite round-trips on everyday pages. Same features and polish.

Changes

Settings — one load of the settings table per request (was one SELECT per get())
Auth — memoize user() for the request; session touch once for members; staff fingerprint/idle still re-checked
Topic view (mods) — batch revision counts (GROUP BY post_id)
Home (logged-in) — single unread-flags query for all recent topics across boards
Large topics — cursor/tail pagination uses LIMIT n+1 instead of separate existence queries

Fedora/RHEL (after COPR rebuild):

sudo dnf upgrade latch
sudo latch doctor

Tarball:

# replace tree, then:
bash scripts/update.sh