feat(events): the minimal admin surface (Phase 3)

Three screens, an Events nav group and the six live run controls Phase 1 left
absent on purpose because nothing was in flight. An admin can now author,
publish, start and watch an event that announces things and cues a human; a
moderator can stop one that is going wrong.

Six controls, not eight. `advance` is absent because a phase today advances when
its steps go terminal — the per-step skip already does that — and Phase 5 is what
gives a phase an advance condition. Cancel takes `{ reason }`, not `{ cleanup }`,
until Phase 8's ledger exists. Every control is a compare-and-set on the status it
may act from, so a console rendered thirty seconds ago cannot act on a run that
has moved.

Fixes a defect in the Phase 2 runner: `advanceRun` drained up to
EVENT_STEPS_PER_TICK steps while only checking the run's status at the top of the
tick, so a pause pressed mid-batch did nothing for up to 24 more steps.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T6t8mrAWhZU5vnyYgZTMtL

client/src/App.jsx

@@ -49,6 +49,9 @@ import EngagementTriggers from './routes/admin/views/EngagementTriggers.jsx'
 import EngagementSendLog from './routes/admin/views/EngagementSendLog.jsx'
 import EngagementSuppressions from './routes/admin/views/EngagementSuppressions.jsx'
 import EngagementRetention from './routes/admin/views/EngagementRetention.jsx'
+import EventsAdmin from './routes/admin/views/EventsAdmin.jsx'
+import EventEditor from './routes/admin/views/EventEditor.jsx'
+import EventRun from './routes/admin/views/EventRun.jsx'
 import TeamsAdmin from './routes/admin/views/TeamsAdmin.jsx'
 import AccountAdmin from './routes/admin/views/AccountAdmin.jsx'
 import Moderation from './routes/admin/views/Moderation.jsx'
@@ -192,6 +195,18 @@ export default function App() {
                   actions that publish a game-written name is applied per request
                   on the server, from the caller's live role (TEAMS.md 2.9). */}
               <Route path="teams" element={<TeamsAdmin />} />
+              {/* Events (EVENTS.md §I, Phase 3). Staff-wide, unlike Engagement:
+                  §K makes every read here `staff`, and the moderator's whole
+                  power over this feature is the run console — cancelling a run
+                  that is doing something wrong at 2am. The narrower gates are
+                  applied per action instead: authoring is admin+editor, publish
+                  and start are admin only (§N2), and each button follows the
+                  route it calls. `runs/:runId` is declared before `:id` so the
+                  literal segment is never read as a definition id. */}
+              <Route path="events" element={<EventsAdmin />} />
+              <Route path="events/runs/:runId" element={<EventRun />} />
+              <Route path="events/new" element={<EventEditor />} />
+              <Route path="events/:id" element={<EventEditor />} />
               {/* Engagement (ENGAGEMENT.md Phases 4b and 5b). Admin-only, matching the
                   server: every route under /admin/engagement re-gates to `admin`
                   on top of the group's staff gate, because this is the group that