feat: add landing page Features, How It Works, and CTA sections

- HowItWorksSection: 3-step staggered timeline with gradient circles
- FeaturesGridSection: 6-card responsive grid (DarkWatch, VoicePrint, SpamShield, HomeTitle, RemoveBrokers, Family Plans)
- ForUsersSection: Split panel for Individuals and Families with checkmark lists
- WhyShieldAISection: 3 value prop cards (Proactive, AI-Powered, Privacy First)
- CTABannerSection: Final CTA with Create Account and Sign In buttons
- Updated routes/index.tsx with clip-path polygon transitions between sections
- Added 49 unit tests for all new sections

web/src/components/landing/index.ts

@@ -1,2 +1,7 @@
-export { default as ColorWaveBackground } from "./ColorWaveBackground";
+export { ColorWaveBackground } from "./ColorWaveBackground";
 export { default as HeroSection } from "./HeroSection";
+export { default as HowItWorksSection } from "./HowItWorksSection";
+export { default as FeaturesGridSection } from "./FeaturesGridSection";
+export { default as ForUsersSection } from "./ForUsersSection";
+export { default as WhyShieldAISection } from "./WhyShieldAISection";
+export { default as CTABannerSection } from "./CTABannerSection";