Add modal={false} to Select/DropdownMenu and polish cast carousel layout

- Set `modal={false}` on all Select and DropdownMenu instances to
  prevent scroll lock and backdrop interference when opened inside
  scrollable or fixed-position containers
- Reduce cast carousel card gap from `gap-4` to `gap-1` and switch
  actor name from `line-clamp-2` to `truncate` for a tighter layout
- Fix backup schedule description layout: move `suppressHydrationWarning`
  to wrapper span, add margin to inline SelectTrigger, use `!h-auto`
  to override default height

components/nav-bar.tsx

@@ -212,7 +212,7 @@ export function NavBar({
             className="mx-1.5 my-auto hidden h-6 bg-border/50 sm:block"
           />
           {/* User avatar dropdown */}
-          <DropdownMenu>
+          <DropdownMenu modal={false}>
             <DropdownMenuTrigger
               className="hidden cursor-pointer rounded-full outline-none ring-2 ring-transparent transition-all hover:ring-primary/40 focus-visible:ring-primary/60 sm:block"
               aria-label="Account menu"