feat: push selected events to a phone over ntfy

Adds a Notifications tab to Settings so an operator can pick which events
reach their phone, published to a single self-hosted ntfy topic.

The notifier subscribes to the realtime event hub the dashboard already
consumes, so every notifiable event keeps exactly one publisher. Inbound
media had no event, so `media.received` is added and published from the
existing durable `gotImage` gate in the chat service — one notification
per conversation, never repeated when the room re-syncs. It feeds the
in-app notification bell as well.

- Best-effort delivery: a rejecting or unreachable ntfy server is logged
  and never propagated into the path that produced the event.
- Events buffered before the notifier attaches are skipped, so a restart
  cannot replay a backlog to somebody's phone.
- Settings are applied field by field onto the live config object, so a
  save takes effect without a restart.
- The access token is environment-owned (NTFY_AUTH_TOKEN) like the other
  secrets: stripped before the settings record is written, never returned
  by the API, which reports only `hasAuthToken`.

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

apps/dashboard/src/features/settings/settings-queries.ts

@@ -1,13 +1,37 @@
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 import type { ConfigResponse } from '../../../../../packages/api-contracts/src/index.js';
 import { fetchLoginStatus, fetchRedditAccounts, fetchSettings, importRedditSession, saveSettings } from './settings-api.js';
+import {
+  fetchPushNotifications,
+  savePushNotifications,
+  sendTestPushNotification,
+} from './push-notifications-api.js';
 
 export const settingsQueryKeys = {
   config: ['dashboard', 'config'] as const,
   loginStatus: ['dashboard', 'login', 'status'] as const,
   accounts: ['dashboard', 'reddit-accounts'] as const,
+  pushNotifications: ['dashboard', 'push-notifications'] as const,
 };
 
+export function usePushNotificationsQuery() {
+  return useQuery({ queryKey: settingsQueryKeys.pushNotifications, queryFn: fetchPushNotifications });
+}
+
+export function useSavePushNotificationsMutation() {
+  const queryClient = useQueryClient();
+  return useMutation({
+    mutationFn: savePushNotifications,
+    onSuccess(response) {
+      queryClient.setQueryData(settingsQueryKeys.pushNotifications, response);
+    },
+  });
+}
+
+export function useTestPushNotificationMutation() {
+  return useMutation({ mutationFn: sendTestPushNotification });
+}
+
 export function useSettingsQuery() {
   return useQuery({ queryKey: settingsQueryKeys.config, queryFn: fetchSettings });
 }