A crowd you can find, and a phone 65px too narrow

Two reports against 1.6.0 and 1.7.0, both correct.

The crowd worked end to end and was, in practice, not there: the picker was
behind the ⋯ menu of a chat that already existed, and the switch was a card on
the Agents page, which made it read as an agent-chat feature. The picker is now
a button in the composer toolbar on both screens that include it, and on the
new-chat screen the choice rides along with the first message, so a chat can
start as a crowd instead of having to be converted into one. The instance
switch has its own page.

The width bug was the suggestion cards, exactly as reported. `.suggestions`
rendered 455px inside a 366px column, and the tree's standing rule applied on
its own made it worse -- 428px to 455px. A grid item carries `min-width: auto`,
which is a min-content floor, and a floor beats `width: 100%`; the floor is
measured while the percentage is indefinite, so `min(100%, …)` alone sends the
track to a card's max-content. Both halves now go on all four auto-fit grids,
and a test refuses either alone.

It survived four releases of narrow-width checking because the harness never
rendered that screen: `TestClient(app)` runs no lifespan outside a `with` block,
so the startup-seeded cards were missing from every shot ever taken of it. And
its overflow check skipped anything inside a scroller -- right for a table in
its own scroller, blind to the scroller itself, which `overflow-y: auto` makes
scroll sideways too. Both fixed; it now names the box and the child to blame.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/lembas/web/static/css/admin.css

@@ -260,7 +260,9 @@ a.tabs__tab { text-decoration: none; }
 */
 .field-row {
   display: grid;
-  grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));
+  /* Both halves of the pair -- see `.grid--2` in app.css. */
+  min-width: 0;
+  grid-template-columns: repeat(auto-fit, minmax(min(100%, 9rem), 1fr));
   gap: var(--sp-3);
 }
 .field-row > .field { margin-bottom: var(--sp-4); }