fix: resolve three critical UI issues

- Fix hero video not displaying in notch safe area by changing z-index from -1 to 1
- Fix lucide icons not showing by installing and configuring nuxt-icon module
- Fix navigation bar bobbing by removing hysteresis thresholds and simplifying scroll handler

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

apps/website/components/HeroSection.vue

@@ -179,7 +179,7 @@ onMounted(() => {
   left: 0;
   width: 100vw;
   height: 100vh;
-  z-index: -1;
+  z-index: 1;
   pointer-events: none;
   background: #ffffff; /* White fallback */
 }