Polish mobile layouts, extract ExpandableText, fix image sizing

- Stack title-hero poster/metadata vertically on mobile (flex-col md:flex-row),
  switch backdrop tall breakpoint from sm to md
- Extract bio expand/collapse logic into reusable ExpandableText component;
  use it in PersonHero and TitleHero
- Fix ContinueWatchingCard image to use fill + sizes instead of fixed
  width/height to avoid layout shift
- Add fade-out gradient on genre chip scrollbar edge on mobile
- Show scaled-down ambient glow on mobile instead of hiding it entirely
- Humanize knownForDepartment labels (Acting→Actor, Directing→Director, etc.)
- Change cast member name from truncate to line-clamp-2 for wrapping
- Hide tooltip arrow via [&>:last-child]:hidden instead of color-matching it
- Apply safe-area-inset padding to HeroBanner content on notched devices

components/ui/scroll-area.tsx

@@ -19,7 +19,7 @@ function ScrollArea({
     >
       <ScrollAreaPrimitive.Viewport
         data-slot="scroll-area-viewport"
-        className="focus-visible:ring-ring/50 size-full rounded-[inherit] transition-[color,box-shadow] outline-none focus-visible:ring-[3px] focus-visible:outline-1"
+        className="size-full rounded-[inherit] outline-none transition-[color,box-shadow] focus-visible:outline-1 focus-visible:ring-[3px] focus-visible:ring-ring/50"
       >
         {children}
       </ScrollAreaPrimitive.Viewport>
@@ -40,14 +40,14 @@ function ScrollBar({
       data-orientation={orientation}
       orientation={orientation}
       className={cn(
-        "flex touch-none p-px transition-colors select-none data-horizontal:h-2.5 data-horizontal:flex-col data-horizontal:border-t data-horizontal:border-t-transparent data-vertical:h-full data-vertical:w-2.5 data-vertical:border-l data-vertical:border-l-transparent",
+        "flex touch-none select-none p-px transition-colors data-horizontal:h-2.5 data-vertical:h-full data-vertical:w-2.5 data-horizontal:flex-col data-horizontal:border-t data-horizontal:border-t-transparent data-vertical:border-l data-vertical:border-l-transparent",
         className,
       )}
       {...props}
     >
       <ScrollAreaPrimitive.Thumb
         data-slot="scroll-area-thumb"
-        className="bg-border relative flex-1 rounded-full"
+        className="relative flex-1 rounded-full bg-border"
       />
     </ScrollAreaPrimitive.Scrollbar>
   );