feat(auth): OIDC phase 4/5/6 — token refresh, logout revocation, account link

- initMatrix.ts: import the shared Session type; when a session has a refresh
  token + oidc metadata, wire a LotusOidcTokenRefresher via createClient's
  refreshToken + tokenRefreshFunction (reactive 401 refresh). Rust crypto is
  unaffected (still keyed on userId/deviceId).
- client/oidcTokenRefresher.ts: OidcTokenRefresher subclass that persists rotated
  tokens back to the fallback session.
- client/oidcLogout.ts + logoutClient: best-effort revoke access+refresh tokens at
  the issuer's revocation_endpoint on logout (tolerant of failure).
- settings/account/OidcManageAccount.tsx: MSC2965 "Manage account" deep-link,
  shown only when authMetadata is present (OIDC servers); mirrors OtherDevices.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/features/settings/account/Account.tsx

@@ -5,6 +5,7 @@ import { MatrixId } from './MatrixId';
 import { Profile } from './Profile';
 import { ContactInformation } from './ContactInfo';
 import { IgnoredUserList } from './IgnoredUserList';
+import { OidcManageAccount } from './OidcManageAccount';
 
 type AccountProps = {
   requestClose: () => void;
@@ -32,6 +33,7 @@ export function Account({ requestClose }: AccountProps) {
             <Box direction="Column" gap="700">
               <Profile />
               <MatrixId />
+              <OidcManageAccount />
               <ContactInformation />
               <IgnoredUserList />
             </Box>