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/api/admin_crowd.py

@@ -0,0 +1,68 @@
+"""The crowd: several models answering one turn, in any chat.
+
+Its own module because it is its own page, and it is its own page because as a card
+on `/admin/agents` it read as an agent-chat feature. It is not one: a crowd works in
+an ordinary conversation, and the owner reasonably concluded otherwise from where
+the switch was sitting.
+"""
+
+from __future__ import annotations
+
+import logging
+
+from fastapi import APIRouter, Form, Request, Response, status
+from fastapi.responses import RedirectResponse
+
+from lembas.api.deps import AdminUser, Db
+from lembas.services import settings_store
+from lembas.web.templating import render
+
+log = logging.getLogger(__name__)
+
+router = APIRouter(prefix="/admin/crowd", tags=["admin-crowd"])
+
+
+@router.get("")
+async def crowd_page(request: Request, db: Db, user: AdminUser, saved: str = ""):
+    """Its own page, for the reason its template records: as a card on the Agents
+    screen it read as an agent-chat feature, which it is not."""
+    return render(
+        request,
+        "admin/crowd.html",
+        {"crowd": settings_store.crowd(db), "saved": saved},
+    )
+
+
+@router.post("")
+async def save_crowd(
+    db: Db,
+    user: AdminUser,
+    enabled: bool = Form(False),
+    max_models: int = Form(4),
+    max_rounds: int = Form(2),
+    wall_seconds: int = Form(900),
+    collapse_agreement: bool = Form(False),
+) -> Response:
+    """One group, one form, one route.
+
+    The bounds are clamped here as well as in `settings_store.crowd`, which is the
+    same belt-and-braces `save_subagents` in `admin_agents.py` uses: a value posted
+    past this route -- by an older page, or by hand -- still reads back sane.
+    """
+    settings_store.update(
+        db,
+        {
+            "enabled": enabled,
+            # Every floor is one: a zero would be the feature switched off
+            # wearing the switch's clothes.
+            "max_models": min(max(max_models, 1), 8),
+            "max_rounds": min(max(max_rounds, 1), 5),
+            "wall_seconds": min(max(wall_seconds, 60), 7200),
+            "collapse_agreement": collapse_agreement,
+        },
+        key=settings_store.CROWD,
+    )
+    log.info("crowd %s by %s", "enabled" if enabled else "disabled", user.email)
+    return RedirectResponse("/admin/crowd?saved=1", status_code=status.HTTP_303_SEE_OTHER)
+
+