feat: replace logo image with native SVG logo in certificate

Remove footer from login, register, instructor-application pages & lighten contact icons color

feat: improve keep-alive workflow with retry logic and 5min interval

update readme file

ci: add keep-alive workflow to prevent Render sleep

feat: notifications page, dynamic metadata, animations, footer, contact, sitemap, rate limit fix

docs: comprehensive README update for social media launch

Update components, backend utils, and frontend dependencies

fix: resolve duplicate token variable declaration in verifyEmail

fix: auto-login after email verification and fix redirect issues

fix: switch to Brevo HTTP API for reliable email delivery on Render

fix: switch from SMTP to Resend HTTP API for email delivery

fix: send emails in background to prevent timeout failures on Render

fix: use explicit SMTP config instead of service preset for reliable email delivery

fix: allow re-registration for unverified accounts and handle email failure gracefully