Auth Session Refresh Banner

Motivation

A browser session can become stale while the Static Web App still has cached UI state. In that case users may see loading or request errors even though the backend is healthy, and signing in again resolves the issue.

User-facing change

When API or ARM token refresh fails, or an authenticated API request returns HTTP 401, the app now shows a top-of-page session banner with a Sign in again action. The action starts a fresh Microsoft Entra login flow with prompt=login.

API/IaC diff summary

• Added a small auth session event helper in web/src/auth/sessionEvents.ts.
• API and ARM clients now publish a session issue event when token state looks stale.
• The main layout now renders a persistent session refresh banner for authenticated pages.
• No backend or IaC changes.

Validation evidence

• npm run build passed.
• azd deploy web --no-prompt deployed the production Static Web App.
• Browser smoke check loaded the production app successfully.
• Injected an elb:auth-session-issue event in the production browser session and verified the session banner plus Sign in again action render.