The four tests that wait on the background debounced write race against
SAVE_DELAY (1.0s): _wait_for_save polls 100 x 0.01s = 1.0s, exactly equal to
the debounce, leaving zero slack. On a loaded CI runner the write lands after
the poll gives up, failing intermittently with 'Recipe open stats file was
never written' (5 of 62 backend runs since the tests landed).
Shrink SAVE_DELAY to 0.05s in _prepare so the write lands ~20x inside the
poll window. The debounce duration is not what these tests verify; production
default stays 1.0s.
Track recipe modal opens in a separate stats file (never touching recipe
JSON/EXIF), expose a fire-and-forget POST endpoint, and add an 'opened'
sort that hides never-opened recipes as a true recently-opened view.
Includes i18n for all locales and backend/frontend tests.