Improve three scene performance and add JSCAD

- smoothed follow mouse animation
- made mobile friendlier down to about 330px ish
- added default social image
- used smaller hero asset

app/web/src/pages/HomePage/HomePage.tsx

@@ -9,6 +9,7 @@ const ProjectsPage = () => {
         title="Home page"
         description="Learn about Code CAD and the CadHub community"
         lang="en-US"
+        socialImageUrl="https://cadhub.xyz/default-social-image.jpg"
       />
       <Hero />
     </MainLayout>

app/web/src/pages/ProjectsPage/ProjectsPage.tsx

@@ -8,6 +8,7 @@ const ProjectsPage = () => {
       <Seo
         title="Projects page"
         description="Cadhub Projects page"
+        socialImageUrl="https://cadhub.xyz/default-social-image.jpg"
         lang="en-US"
       />
       <div className="bg-ch-gray-800 pb-64">