feat: remember original URL and redirect after login (#18308)

## Summary

- Implement a return-to-path mechanism that preserves the user's
intended destination across authentication flows (login, magic link,
cross-domain redirects)
- Uses layered persistence: Jotai atom (in-memory), sessionStorage with
TTL (tab-switch resilience), URL query parameter (cross-domain
propagation)
- Includes path validation to prevent open redirects, automatic cleanup
after successful login, and comprehensive test coverage
- Replaces the unused `previousUrlState` with a robust
`returnToPathState` system

## Test plan

- [ ] Visit a deep link (e.g. `/objects/tasks`) while logged out —
should redirect to login, then back to `/objects/tasks` after logging in
- [ ] Visit an OAuth authorize link while logged out — should redirect
to login, then to the authorize page
- [ ] Test magic link flow: click sign-in link that opens new tab —
should still redirect to original destination
- [ ] Test cross-domain: visit `app.twenty.com/objects/tasks` — should
preserve path through workspace domain redirect
- [ ] Verify auth/onboarding paths are excluded from being saved as
return paths
- [ ] Verify return-to-path is cleared after successful navigation
- [ ] All 215 existing `usePageChangeEffectNavigateLocation` tests pass


Made with [Cursor](https://cursor.com)

packages/twenty-front/src/modules/workspace/components/WorkspaceProviderEffect.tsx

@@ -12,6 +12,9 @@ import { isDefined } from 'twenty-shared/utils';
 import { type WorkspaceUrls } from '~/generated-metadata/graphql';
 import { getWorkspaceUrl } from '~/utils/getWorkspaceUrl';
 
+const getCurrentSearchParams = (): Record<string, string> =>
+  Object.fromEntries(new URLSearchParams(window.location.search));
+
 export const WorkspaceProviderEffect = () => {
   const { data: getPublicWorkspaceData } = useGetPublicWorkspaceDataByDomain();
 
@@ -48,6 +51,8 @@ export const WorkspaceProviderEffect = () => {
     ) {
       redirectToWorkspaceDomain(
         getWorkspaceUrl(getPublicWorkspaceData.workspaceUrls),
+        window.location.pathname,
+        getCurrentSearchParams(),
       );
     }
   }, [
@@ -67,7 +72,11 @@ export const WorkspaceProviderEffect = () => {
       isDefined(lastAuthenticatedWorkspaceDomain?.workspaceUrl)
     ) {
       initializeQueryParamState();
-      redirectToWorkspaceDomain(lastAuthenticatedWorkspaceDomain.workspaceUrl);
+      redirectToWorkspaceDomain(
+        lastAuthenticatedWorkspaceDomain.workspaceUrl,
+        window.location.pathname,
+        getCurrentSearchParams(),
+      );
     }
   }, [
     isMultiWorkspaceEnabled,