feat(links): Copy Lotus Link permalinks, in-app recognition, /home redirect for joined rooms, via= alias, OIDC deep-link redirect (#130)

matrix.to cannot target this deployment (Cinny adapter hard-codes
app.cinny.in; web-instance[] is Element-only, allowlisted), so add a
"Copy Lotus Link" next to every Copy Link (message menu, space header
menu, sidebar space tab) producing https://<this origin>/home/<room>/<event>
?viaServers=… via plugins/lotus-permalink.ts. Lotus links in messages are
rewritten to their matrix.to form inside the HTML parser so they render as
room/event mentions and navigate in place.

/home/<room> for a joined room that belongs to a space or Direct now
redirects to its own route (was a preview card with a View button; also
the form matrix.to → Cinny links use). ?via= is accepted as an alias of
?viaServers= (what the matrix.to Cinny adapter emits). A deep link
visited while logged out is now honoured after an OIDC login: the OIDC
callback reloads at the app root, which discarded the stored path — the
index loader consumes it via the shared takeAfterLoginPath().

Verified end-to-end with Playwright on a local Synapse: logged-out cold
link → login → lands on the event under the space route; menu copies the
expected link; a pasted Lotus link renders as a mention and jumps in
place; both space menus copy the space link.

Closes #130

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/pages/auth/login/loginUtil.ts

@@ -5,10 +5,7 @@ import { useNavigate } from 'react-router-dom';
 import { ClientConfig, clientAllowedServer } from '../../../hooks/useClientConfig';
 import { autoDiscovery, specVersions } from '../../../cs-api';
 import { ErrorCode } from '../../../cs-errorcode';
-import {
-  deleteAfterLoginRedirectPath,
-  getAfterLoginRedirectPath,
-} from '../../afterLoginRedirectPath';
+import { takeAfterLoginPath } from '../../afterLoginRedirectPath';
 import { getHomePath } from '../../pathUtils';
 import { setFallbackSession } from '../../../state/sessions';
 
@@ -115,11 +112,7 @@ export const useLoginComplete = (data?: CustomLoginResponse) => {
     if (data) {
       const { response: loginRes, baseUrl: loginBaseUrl } = data;
       setFallbackSession(loginRes.access_token, loginRes.device_id, loginRes.user_id, loginBaseUrl);
-      const afterLoginRedirectUrl = getAfterLoginRedirectPath();
-      deleteAfterLoginRedirectPath();
-      const _redir = afterLoginRedirectUrl;
-      const _safePath = _redir && /^\/(?!\/)/.test(_redir) ? _redir : getHomePath();
-      navigate(_safePath, { replace: true });
+      navigate(takeAfterLoginPath(getHomePath()), { replace: true });
     }
   }, [data, navigate]);
 };