The operator, on the live Desk: "how is this last activity first?" It was not,
usefully. The section sorted by `_newest_mtime`, which counts a look (`.viewed`),
so opening a booth moved it up. Tonight two post-deploy checks fetched every
booth page within half a second, which recorded 22 looks at once and collapsed
the section into reverse name order through the (mtime, name) tie-break.
Meanwhile each row shows "updated X ago", which is `landed_at`, a different
clock from the one the list was sorted by.
Operator ruling: "last activity can just be last time the booth was updated,
not necessarily operator's last activity." The section now sorts by
`(-landed_at, name)`, the date the row shows, labelled "last updated first".
Looking, flagging and blurring no longer move a booth. `list_booths` keeps its
own order for its other readers, and `_newest_mtime` still feeds lifetime.
The r2_flow contract (§3, the ordering table, INV-5) and ROADMAP's ordering row
are amended to match. Two tests and two r2_flow.toml rows cover it (25/25).