Strip AI tooling and working docs for dev push

Hero heading was display3 (same as every section h2), giving no visual
distinction. Now display2 (52px/24px) vs display3 (40px/22px). Still
renders as semantic h1 for SEO.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/pages/HomePage/HomePage.tsx

@@ -251,7 +251,7 @@ export const HomePage = React.forwardRef<HTMLDivElement, HomePageProps>(
                 }}
               >
                 <Typography
-                  variant="display3"
+                  variant="display2"
                   component="h1"
                   id="hero-heading"
                   tabIndex={-1}
@@ -316,7 +316,7 @@ export const HomePage = React.forwardRef<HTMLDivElement, HomePageProps>(
                   }}
                 >
                   <Typography
-                    variant="display3"
+                    variant="display2"
                     component="h1"
                     id="hero-heading"
                     tabIndex={-1}