Redesign React auth pages

[singhanurag0317-bit]

Summary

• redesign the existing React login and signup pages with the soft-blue glassmorphism style from issue frontend:deign the signup,login and email verification page #82
• add a dedicated email verification screen matching the reference envelope/check design
• share reusable auth layout, card, input, button, social-login, stepper, and illustration components across auth screens
• wire successful signup to the verification step before continuing to the existing profile setup flow

Notes

• Kept the implementation in the existing Vite React app; no Next.js migration or backend contract changes.
• The verification page is a frontend step with a resend action placeholder, preserving the current signup API behavior.

Testing

• npm.cmd run build
• npm.cmd run lint
• Browser visual check for login and signup screens at http://127.0.0.1:5173

Closes #82