PCO Plan 1.10.0: follow several service types in priority order, and read any of them from any dashboard

An account runs more than one service type — a Sunday morning, a Wednesday
night, a youth service, a second campus — and until now that meant one
ProdDash per type. The module now follows as many as are configured.

Admin picks them in priority order. Shell 1.12.0 gives `multiselect` an
`orderable: true` that stops being a ticklist: the picks sit in a numbered
list with a nudge either way and a remove, over a dropdown holding what is
left. Forty switches to read past is not a picker, and a ticklist cannot
carry an order anyway. The order is the setting — when two types have a plan
at the same date and time, the one higher up wins.

The server gathers candidate plans from every ticked type and tiers them:
today's plan first, then the next upcoming, then the most recent past, with
the configured order breaking a tie. A type that fails is skipped rather
than failing the read, unless it is an auth or rate-limit answer, which
belongs to the whole connection. The types not being followed are read on a
slower lane (45 s) into `state.others`, so they are there to look at without
a second connection.

Every tile's title bar carries a service-type control. Picking one moves
every PCO Plan tile on that browser's dashboard — plan, teams and song key
together — onto its plan, over a small page bus in `viewed-type.js`; the
choice is per browser and survives a reload. The control hides itself when
only one type is configured.

Live machinery stays with the type being followed: another type's plan shows
its running order with no now marker, no AbleSet and no service clock — it
shows that plan's own scheduled time instead, since borrowing the running
clock of a different service is exactly the misreading the amber top-bar
stripe exists to prevent.

Old configs carry `serviceTypeId`; it is read once into the new array and
saved, and plan pins still resolve bare, so nothing has to be re-entered.

`tools/pco-mock.js` takes `--types N` to pad the list out, for trying the
picker against an account with dozens of them.

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

public/admin/admin.css

@@ -648,3 +648,55 @@ details.admin-fold > summary.admin-fold-title:hover { color: var(--accent); }
   gap: 8px;
   margin-left: auto;
 }
+
+/* an orderable multiselect (manifest `"orderable": true`): not a ticklist but
+   a list built on purpose — the picks, numbered, each with a nudge either way
+   and a way out, over a dropdown holding whatever is left to add. Their
+   position is the setting, so it has to be visible and movable. */
+.multiselect-row.is-picked {
+  gap: 6px;
+  cursor: default;
+  padding: 4px 7px;
+  background: var(--bg);
+  border: 1px solid var(--border);
+  border-radius: 7px;
+}
+.multiselect-add {
+  width: 100%;
+  margin-top: 2px;
+  padding: 7px 9px;
+  font-size: 13px;
+  font-family: inherit;
+  color: var(--text);
+  background: var(--bg);
+  border: 1px solid var(--border);
+  border-radius: 7px;
+  cursor: pointer;
+}
+.multiselect-add:focus { outline: none; border-color: var(--accent); }
+.multiselect-add:disabled { color: var(--muted); cursor: default; }
+.multiselect-rank {
+  flex: none;
+  min-width: 16px;
+  font-size: 11px;
+  font-weight: 700;
+  font-variant-numeric: tabular-nums;
+  text-align: right;
+  color: var(--accent);
+}
+.multiselect-row .switch-label { flex: 1; min-width: 0; }
+.multiselect-move {
+  flex: none;
+  width: 20px;
+  height: 20px;
+  padding: 0;
+  line-height: 1;
+  font-size: 9px;
+  color: var(--muted);
+  background: var(--bg);
+  border: 1px solid var(--border);
+  border-radius: 5px;
+  cursor: pointer;
+}
+.multiselect-move:hover:not(:disabled) { color: var(--text); border-color: var(--accent); }
+.multiselect-move:disabled { opacity: 0.3; cursor: default; }