Fix jarring scroll with linear constant-speed motion

- Replace easeInOutSine with linear easing (return t)
- Reduce duration from 1200ms to 800ms for snappier feel
- Update all component references to use new duration

Linear easing provides constant-speed scrolling without any
acceleration or deceleration, eliminating the jarring effect.

apps/website/components/HeroSection.vue

@@ -101,11 +101,11 @@ const handlePhoneClick = () => {
 }
 
 const handleServicesClick = () => {
-  scrollToElement('#services', 1200) // Smooth scrolling with sine easing
+  scrollToElement('#services', 800) // Constant-speed smooth scrolling
 }
 
 const handleScrollToExplore = () => {
-  scrollToElement('#services', 1200) // Smooth scroll to services section
+  scrollToElement('#services', 800) // Constant-speed scroll to services
 }
 
 const handleVideoVisibility = () => {
@@ -136,7 +136,7 @@ const initSmoothScroll = () => {
       if (!href) {
         return
       }
-      scrollToElement(href, 1200) // Smooth scrolling with sine easing
+      scrollToElement(href, 800) // Constant-speed smooth scrolling
     })
   })
 }