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/Router.tsx

@@ -46,7 +46,7 @@ import { Home, HomeRouteRoomProvider, HomeSearch } from './client/home';
 import { Direct, DirectCreate, DirectRouteRoomProvider } from './client/direct';
 import { RouteSpaceProvider, Space, SpaceRouteRoomProvider, SpaceSearch } from './client/space';
 
-import { setAfterLoginRedirectPath } from './afterLoginRedirectPath';
+import { setAfterLoginRedirectPath, takeAfterLoginPath } from './afterLoginRedirectPath';
 
 import { WelcomePage } from './client/WelcomePage';
 import { SidebarNav } from './client/SidebarNav';
@@ -112,7 +112,10 @@ export const createRouter = (clientConfig: ClientConfig, screenSize: ScreenSize)
       <Route
         index
         loader={() => {
-          if (getFallbackSession()) return redirect(getHomePath());
+          // A stored deep link is normally consumed by the password login;
+          // the OIDC callback instead reloads at the app root, so consume it
+          // here too (Gitea #130 — SSO users landing on a shared room link).
+          if (getFallbackSession()) return redirect(takeAfterLoginPath(getHomePath()));
           const afterLoginPath = getAppPathFromHref(getOriginBaseUrl(), window.location.href);
           if (afterLoginPath) setAfterLoginRedirectPath(afterLoginPath);
           return redirect(getLoginPath());