refactor(web): consume DS primitives, remove local component copies

Replace locally-forked UI components and hooks with their newly
promoted counterparts from @nous-research/ui:

Deleted local components (now in DS):
- components/ui/input.tsx, label.tsx, separator.tsx, card.tsx,
  confirm-dialog.tsx
- components/Toast.tsx, BottomPickSheet.tsx, NouiTypography.tsx
- hooks/useToast.ts, useModalBehavior.ts, useBelowBreakpoint.ts,
  useConfirmDelete.ts

Import updates across 25 files to use DS deep imports:
- @nous-research/ui/ui/components/{input,label,separator,card,
  confirm-dialog,toast,bottom-sheet}
- @nous-research/ui/ui/components/typography (replaces NouiTypography)
- @nous-research/ui/hooks/{use-toast,use-modal-behavior,
  use-below-breakpoint,use-confirm-delete}

Requires design-language >= feat/promote-hermes-web-primitives.

Co-authored-by: Cursor <cursoragent@cursor.com>

web/src/components/LanguageSwitcher.tsx

@@ -1,8 +1,8 @@
 import { useState, useRef, useEffect } from "react";
 import { Button } from "@nous-research/ui/ui/components/button";
-import { BottomPickSheet } from "@/components/BottomPickSheet";
-import { Typography } from "@/components/NouiTypography";
-import { useBelowBreakpoint } from "@/hooks/useBelowBreakpoint";
+import { BottomSheet } from "@nous-research/ui/ui/components/bottom-sheet";
+import { Typography } from "@nous-research/ui/ui/components/typography";
+import { useBelowBreakpoint } from "@nous-research/ui/hooks/use-below-breakpoint";
 import { useI18n } from "@/i18n/context";
 import { LOCALE_META } from "@/i18n";
 import type { Locale } from "@/i18n";
@@ -82,7 +82,7 @@ export function LanguageSwitcher({ dropUp = false }: LanguageSwitcherProps) {
       </Button>
 
       {useMobileSheet && (
-        <BottomPickSheet
+        <BottomSheet
           backdropDismissLabel={t.common.close}
           onClose={() => setOpen(false)}
           open={open}
@@ -96,7 +96,7 @@ export function LanguageSwitcher({ dropUp = false }: LanguageSwitcherProps) {
               setOpen={setOpen}
             />
           </div>
-        </BottomPickSheet>
+        </BottomSheet>
       )}
 
       {open && !useMobileSheet && (