Add /auth/refresh endpoint to issue new access tokens using refresh tokens with token type validation and user activity checks, implement automatic token refresh on 401 responses with single retry logic in frontend API client, add authorizedFetch helper for non-JSON endpoints with refresh support, store both access and refresh tokens in localStorage with clearTokens cleanup helper, add nexafabric.authExpired event
Normalize email input by stripping whitespace and converting to lowercase in login endpoint, remove EmailStr validation in favor of plain string type, move dark mode class toggle from Layout to App component for better initialization, add theme toggle button to login page, and set dark mode as default theme when no preference is stored