feat: server support contact display (MSC1929) and server notices UI

- Settings Help/About fetches /.well-known/matrix/support and displays
  admin contact + support page link (graceful 404 degradation)
- Server notice rooms (m.server_notice) now show a Warning badge in the
  room header and hide the message composer

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/features/room/RoomInput.tsx

@@ -603,6 +603,16 @@ export const RoomInput = forwardRef<HTMLDivElement, RoomInputProps>(
       });
     };
 
+    if (room.getType() === 'm.server_notice') {
+      return (
+        <div ref={ref} style={{ padding: config.space.S300, textAlign: 'center' }}>
+          <Text size="T300" priority="300">
+            This is a server notice room — you cannot send messages here.
+          </Text>
+        </div>
+      );
+    }
+
     return (
       <div ref={ref}>
         {selectedFiles.length > 0 && (

src/app/features/settings/about/About.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { useEffect, useState } from 'react';
 import { Box, Text, IconButton, Icon, Icons, Scroll, Button, config, toRem } from 'folds';
 import { Page, PageContent, PageHeader } from '../../../components/page';
 import { SequenceCard } from '../../../components/sequence-card';
@@ -8,12 +8,49 @@ import LotusLogo from '../../../../../public/res/Lotus.png';
 import pkg from '../../../../../package.json';
 import { clearCacheAndReload } from '../../../../client/initMatrix';
 import { useMatrixClient } from '../../../hooks/useMatrixClient';
+import { lotusTerminalBodyClass } from '../../../../lotus-terminal.css';
+
+type MSC1929Contact = {
+  matrix_id?: string;
+  email_address?: string;
+  role?: string;
+};
+
+type MSC1929Support = {
+  contacts?: MSC1929Contact[];
+  support_page?: string;
+};
+
+function useServerSupport(): MSC1929Support | null {
+  const mx = useMatrixClient();
+  const [support, setSupport] = useState<MSC1929Support | null>(null);
+
+  useEffect(() => {
+    const baseUrl = (mx as unknown as { baseUrl: string }).baseUrl;
+    fetch(`${baseUrl}/.well-known/matrix/support`)
+      .then((res) => {
+        if (!res.ok) return null;
+        return res.json() as Promise<MSC1929Support>;
+      })
+      .then((data) => {
+        if (data && (data.contacts?.length || data.support_page)) {
+          setSupport(data);
+        }
+      })
+      .catch(() => {
+        // Graceful degradation — server may not have this configured
+      });
+  }, [mx]);
+
+  return support;
+}
 
 type AboutProps = {
   requestClose: () => void;
 };
 export function About({ requestClose }: AboutProps) {
   const mx = useMatrixClient();
+  const serverSupport = useServerSupport();
 
   return (
     <Page>
@@ -108,6 +145,67 @@ export function About({ requestClose }: AboutProps) {
                   />
                 </SequenceCard>
               </Box>
+              {serverSupport && (
+                <Box direction="Column" gap="100">
+                  <Text size="L400">Homeserver Support</Text>
+                  <SequenceCard
+                    className={SequenceCardStyle}
+                    variant="SurfaceVariant"
+                    direction="Column"
+                    gap="400"
+                  >
+                    <Box direction="Column" gap="200" style={{ padding: config.space.S200 }}>
+                      {serverSupport.contacts && serverSupport.contacts.length > 0 && (
+                        <Box direction="Column" gap="100">
+                          {serverSupport.contacts.map((contact, i) => (
+                            <Box key={i} alignItems="Center" gap="200">
+                              <Text size="T300" priority="300">
+                                {contact.role === 'm.role.admin'
+                                  ? 'Admin'
+                                  : contact.role === 'm.role.security'
+                                    ? 'Security'
+                                    : 'Contact'}
+                                :
+                              </Text>
+                              <Text
+                                size="T300"
+                                style={{
+                                  color: document.body.classList.contains(lotusTerminalBodyClass)
+                                    ? 'var(--lt-accent-cyan)'
+                                    : undefined,
+                                }}
+                              >
+                                {contact.matrix_id ?? contact.email_address ?? ''}
+                              </Text>
+                            </Box>
+                          ))}
+                        </Box>
+                      )}
+                      {serverSupport.support_page && (
+                        <Box alignItems="Center" gap="200">
+                          <Text size="T300" priority="300">
+                            Support Page:
+                          </Text>
+                          <Text size="T300">
+                            <a
+                              href={serverSupport.support_page}
+                              target="_blank"
+                              rel="noreferrer noopener"
+                              style={{
+                                color: document.body.classList.contains(lotusTerminalBodyClass)
+                                  ? 'var(--lt-accent-cyan)'
+                                  : undefined,
+                              }}
+                            >
+                              {serverSupport.support_page}
+                            </a>
+                          </Text>
+                        </Box>
+                      )}
+                    </Box>
+                  </SequenceCard>
+                </Box>
+              )}
               <Box direction="Column" gap="100">
                 <Text size="L400">Credits</Text>
                 <SequenceCard