- C-3.7: fold a per-link password_version into the signed watch grant (migration
0059 adds the column) and bump it on every password change, so rotating a share
link's password invalidates outstanding grants at once instead of letting them
live out the 6h TTL. make_grant/check_grant take the version; update_link bumps.
- C-3.8: the share recipient picker and share-by-email now reuse the messageable
filter (not-demo AND active AND not-suspended) instead of only excluding demo,
so suspended/deactivated addresses aren't leaked or reachable as targets.
- C-3.9: GET /keys/{user_id} adopts get_thread's MB2 guard — a non-messageable
target with no shared history returns the same "User not found" as a missing id,
so it can't be probed to enumerate users or fetch suspended users' keys.
- C-3.12: _register_account catches IntegrityError on the insert (the select-then-
insert TOCTOU) and treats it as the already-registered no-op.
- C-3.13: trigger_job claims the running flag atomically under _activity_lock
(compare-and-set) instead of a bare check, closing the double-start window.
- Move _messageable/is_messageable_user into a shared app/userscope.py so downloads
doesn't import the messages route module.
peter
733b41fd86