fix: redirect lost after Pangolin auth session timeout (#3001)

[Adityakk9031]

Problem
When a user's Pangolin session expires (org maxSessionLengthHours policy) and they visit a protected resource, they are correctly redirected to /auth/resource/{guid}?redirect=https://myservice.mydomain.com. However, after re-authenticating, they stay on pangolin.mydomain.com instead of being sent to myservice.mydomain.com.

It only works correctly if the user manually logs out first.

Root Cause
In src/app/auth/resource/[resourceGuid]/page.tsx, redirectUrl is correctly computed from the ?redirect query param. But when the org policy check fails (maxSessionLength.compliant = false), the page renders without passing redirectUrl. That component had a hardcoded button sending the user to the Pangolin dashboard — the redirect was permanently lost.

Fix
page.tsx — constructs resourceAuthPageUrl (the resource auth page with the ?redirect param preserved) and passes it as redirectAfterAuth to
OrgPolicyRequired.tsx — detects maxSessionLength policy failure and renders a dedicated "Session Expired" card with a "Re-authenticate" button that calls POST /auth/logout then navigates back to the resource auth page. Without a session, the page shows the login form and after login correctly redirects to the original resource
en-US.json — adds sessionExpired, sessionExpiredReauthRequired, and reauthenticate translation keys
Fixed Flow

Session expired → visit myservice.mydomain.com
→ /auth/resource/{guid}?redirect=https://myservice.mydomain.com
→ "Session Expired" card shown
→ click "Re-authenticate"
→ logout + navigate back to /auth/resource/{guid}?redirect=https://myservice.mydomain.com
→ login form shown (no session now)
→ login → redirected to https://myservice.mydomain.com ✓
Files Changed
src/app/auth/resource/[resourceGuid]/page.tsx
src/components/OrgPolicyRequired.tsx
messages/en-US.json
Fixes
Closes #3001