feat: homeserver status banner from Uptime Kuma (#124)

When the homeserver, voice calls or sign-in break, or maintenance is under
way, say so in the app — driven by the Kuma status page
(isitup.lotusguild.org/status/matrix), managed from Kuma's UI. The client
asks Kuma directly (not via our servers) so it still hears "the server is
down" when our servers can't tell it.

- config.json `statusPages`, keyed by homeserver: users of other servers
  never contact Kuma.
- utils/kumaStatus.ts (pure, unit-tested): parse Kuma 2.x's public JSON;
  a group is down when any monitor fails two checks in a row (down+down or
  pending+down); maintenance = windows under way; announcements = incidents.
  One strip at a time: server down (connection lost AND Kuma confirms) >
  server having problems > maintenance > calls down > announcement;
  sign-in problems on the login screen only.
- Wording about the user's own connection: "Connection lost … our status
  checks say the server is up, so it may be your internet connection" ONLY
  when Kuma checked the server after this client's connection dropped and
  it passed; a stale "up" (Kuma needs a minute or two to notice an outage)
  keeps the plain "Connection Lost!".
- useServerStatus: polls only while visible; 5 min, 60 s while something is
  wrong or the connection is lost, at once when it drops; backoff; any
  failure = no banner (Kuma being unreachable never looks like Matrix
  being down); GET only, no cookies.
- UI in the existing banner slot and style (ContainerColor/Line like the
  sync and clock banners); Details expands; dismiss for calls-down and
  announcements (an edited announcement comes back); calls-down note above
  Join; phone: one line + Details.

Needs the CSP connect-src to allow https://isitup.lotusguild.org (matrix
repo) before it can fetch in production; until then it fails quiet.

Tests: 15 unit tests (live page layout, two-check rule, any-monitor rule,
unknown/garbage, UTC beat times, stale-vs-fresh "up", priorities, login vs
client, maintenance, announcements + dismiss/edit); e2e (fixtures for Kuma):
calls-down strip + dismiss across reload, other homeservers make no
requests, Kuma 500 → nothing, lost connection + Kuma down → critical strip
instead of "Connection Lost", + fresh "up" → "may be your connection",
+ stale "up" → plain "Connection Lost". Unit 1315, Playwright 26 passed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/pages/client/ClientRoot.tsx

@@ -44,6 +44,10 @@ import { useSyncState } from '../../hooks/useSyncState';
 import { stopPropagation } from '../../utils/keyboard';
 import { SyncStatus } from './SyncStatus';
 import { ClockSkewBanner } from './ClockSkewBanner';
+import {
+  ServerStatusBanner,
+  ServerStatusFeature,
+} from '../../features/server-status/ServerStatusBanner';
 import { AuthMetadataProvider } from '../../hooks/useAuthMetadata';
 import { getFallbackSession, removeFallbackSession } from '../../state/sessions';
 import { pushSessionToSW } from '../../../sw-session';
@@ -245,6 +249,8 @@ export function ClientRoot({ children }: ClientRootProps) {
   return (
     <AutoDiscovery userId={userId!} baseUrl={baseUrl!}>
       <SpecVersions baseUrl={baseUrl!}>
+        {mx && <ServerStatusFeature mx={mx} />}
+        {mx && !syncError && <ServerStatusBanner />}
         {mx && !syncError && <SyncStatus mx={mx} />}
         {mx && !syncError && <ClockSkewBanner />}
         {loading && <ClientRootOptions mx={mx} />}

src/app/pages/client/SyncStatus.tsx

@@ -1,8 +1,11 @@
 import { MatrixClient, SyncState } from 'matrix-js-sdk';
 import React, { useCallback, useState } from 'react';
+import { useAtomValue } from 'jotai';
 import { Box, config, Line, Text } from 'folds';
 import { useSyncState } from '../../hooks/useSyncState';
 import { ContainerColor } from '../../styles/ContainerColor.css';
+import { serverStatusAtom } from '../../state/serverStatus';
+import { serverConfirmedUpSince } from '../../utils/kumaStatus';
 
 type StateData = {
   current: SyncState | null;
@@ -13,6 +16,7 @@ type SyncStatusProps = {
   mx: MatrixClient;
 };
 export function SyncStatus({ mx }: SyncStatusProps) {
+  const serverStatus = useAtomValue(serverStatusAtom);
   const [stateData, setStateData] = useState<StateData>({
     current: null,
     previous: undefined,
@@ -53,7 +57,14 @@ export function SyncStatus({ mx }: SyncStatusProps) {
     );
   }
 
-  if (stateData.current === SyncState.Reconnecting) {
+  // [Gitea #124] When Kuma confirms the homeserver is down, the status banner
+  // says so ("Lotus Chat's server is down…") instead of "Connection Lost!".
+  const serverDown = serverStatus.status?.homeserver === 'down';
+  // Only blame the user's connection when Kuma has checked the server since
+  // the drop and it was fine (a stale "up" from before proves nothing).
+  const serverUp = serverConfirmedUpSince(serverStatus.status, serverStatus.lostAt);
+
+  if (stateData.current === SyncState.Reconnecting && !serverDown) {
     return (
       <Box direction="Column" shrink="No">
         <Box
@@ -64,14 +75,18 @@ export function SyncStatus({ mx }: SyncStatusProps) {
           role="status"
           aria-live="polite"
         >
-          <Text size="L400">Connection Lost! Reconnecting...</Text>
+          <Text size="L400">
+            {serverUp
+              ? "Connection lost. Our status checks say Lotus Chat's server is up, so it may be your internet connection. Reconnecting…"
+              : 'Connection Lost! Reconnecting...'}
+          </Text>
         </Box>
         <Line variant="Warning" size="300" />
       </Box>
     );
   }
 
-  if (stateData.current === SyncState.Error) {
+  if (stateData.current === SyncState.Error && !serverDown) {
     return (
       <Box direction="Column" shrink="No">
         <Box
@@ -82,7 +97,11 @@ export function SyncStatus({ mx }: SyncStatusProps) {
           role="alert"
           aria-live="assertive"
         >
-          <Text size="L400">Connection Lost!</Text>
+          <Text size="L400">
+            {serverUp
+              ? "Connection lost. Our status checks say Lotus Chat's server is up, so check your internet connection."
+              : 'Connection Lost!'}
+          </Text>
         </Box>
         <Line variant="Critical" size="300" />
       </Box>