feat(ui): premium auth pages polish
AuthLayout:
- Full-screen gradient background with animated pulse blobs
- Glass-morphism card (bg-card/80, backdrop-blur-md, shadow-2xl)
- New animate-auth-enter animation (fade + scale + translateY)
OAuth buttons: real provider icons (Google SVG, GitHub, Discord)
Password strength: 4-segment bar, color-coded labels, checklist icons
Login: Checkbox component for Remember Me, animated error alerts
Register: migrated to AuthInput, username check with spinner/icons
Verification notice: Mail icon, success-tinted circle, AuthButton
Co-authored-by: Cursor <cursoragent@cursor.com>
9f108e2430