Add a global, colour-coded team selector to the nav

state.js's currentTeam() was hard-coded to teams[0] and never really meant
"the team currently selected" — team.js's settings page and queue.js's
filter chips each kept their own separate, unsynchronized notion of "which
team" instead, so picking one on one page had no effect on the other.

Replaces both with a single state.selectedTeamID, set only through the new
setSelectedTeam (persisted in localStorage, unlike the queue's old per-tab
sessionStorage filter) and broadcast to listeners via onTeamChange. A new
teamselector.js control — a coloured dot plus the team's name, or "All
teams" — sits at the top of both the desktop sidebar and the mobile topbar,
opening the existing bottom-sheet menu to switch. Shown only once someone is
in more than one team, matching every other team-aware control in this app.

Colours come from a new teamColorClass() in format.js, hashing a team's id
into the six-colour rc1..rc6 palette already used for the rota's per-person
chips, so no schema or API change is needed. The queue's team filter chips
pick up the same colours.

internal/web/static/js/queue.js

@@ -2,8 +2,8 @@
 
 import * as api from './api.js';
 import { h, clear, badge, emptyState, spinner } from './ui.js';
-import { age, until, isFuture, severityClass, labelSummary } from './format.js';
-import { state, myID } from './state.js';
+import { age, until, isFuture, severityClass, labelSummary, teamColorClass } from './format.js';
+import { state, myID, setSelectedTeam, onTeamChange } from './state.js';
 import * as onboarding from './onboarding.js';
 import { navigate } from './app.js';
 
@@ -27,34 +27,21 @@ const EMPTY = {
 };
 
 onboarding.onRerender(() => renderList());
+// The queue used to keep its own team filter (a per-tab sessionStorage value,
+// out of step with team.js's own picker); both now defer to the global
+// selector's shared state, so re-render whenever it changes.
+onTeamChange(() => {
+  renderChips();
+  refresh({ fresh: true });
+});
 
 let filter = loadFilter();
-let teamFilter = loadTeamFilter(); // '' for every team the viewer is in
 let items = null; // null while loading
 let error = null;
 let selected = null;
 let cursor = -1; // keyboard position in the list
 let built = false;
 
-function loadTeamFilter() {
-  try {
-    return sessionStorage.getItem('terdut.queue.team') || '';
-  } catch {
-    return '';
-  }
-}
-
-function setTeamFilter(id) {
-  teamFilter = id;
-  try {
-    sessionStorage.setItem('terdut.queue.team', id);
-  } catch {
-    /* storage unavailable */
-  }
-  renderChips();
-  refresh({ fresh: true });
-}
-
 function loadFilter() {
   try {
     const f = sessionStorage.getItem('terdut.queue.filter');
@@ -89,8 +76,8 @@ export async function refresh({ fresh = false } = {}) {
     // The open list is already fetched for the badges; no need to ask twice.
     // The cached open queue covers every team, so it can only be reused when
     // no team filter is applied.
-    const query = teamFilter ? { ...f.query, team_id: teamFilter } : f.query;
-    const cached = filter === 'open' && !fresh && !teamFilter;
+    const query = state.selectedTeamID != null ? { ...f.query, team_id: state.selectedTeamID } : f.query;
+    const cached = filter === 'open' && !fresh && state.selectedTeamID == null;
     const result = cached ? state.open : await api.incidents(query);
     await onboarding.load();
     if (requested !== filter) return;
@@ -136,19 +123,20 @@ function renderChips() {
       class: 'chip',
       type: 'button',
       role: 'tab',
-      'aria-selected': String(teamFilter === ''),
-      onclick: () => setTeamFilter(''),
-      text: 'All teams',
-    }));
+      'aria-selected': String(state.selectedTeamID == null),
+      onclick: () => setSelectedTeam(null),
+    }, h('span', { class: 'team-dot' }), ' All teams'));
     for (const team of state.teams) {
       chips.push(h('button', {
         class: 'chip',
         type: 'button',
         role: 'tab',
-        'aria-selected': String(teamFilter === String(team.id)),
-        onclick: () => setTeamFilter(String(team.id)),
-        text: team.name,
-      }));
+        'aria-selected': String(team.id === state.selectedTeamID),
+        onclick: () => setSelectedTeam(team.id),
+      },
+        h('span', { class: `team-dot ${teamColorClass(team.id)}` }),
+        ' ' + team.name,
+      ));
     }
   }