fix: harden update pipeline and restore a clean production build

- update-Nitrov3.sh: build CMS into .next-staging and swap atomically so a
  failed build never takes the live site down; auto-merge new variables
  from .env.example; validate env for duplicates/broken lines; restart the
  emulator/CMS only when rebuilt or unhealthy; fix step renumbering
- next.config.ts: support NEXT_DIST_DIR for staged production builds
- fix all TS errors (unused imports, missing tryDownloadCandidates helper)
  so tsc and the production build pass clean
- add Dockerfile/.dockerignore and switch docker-compose to a CMS container
- include prevailing UI/refactor changes (SurfaceCard, ticketing, tsconfig)

src/components/ui/dialog.tsx

@@ -33,24 +33,6 @@ function DialogPortal({ ...props }: DialogPrimitive.Portal.Props) {
 	return <DialogPrimitive.Portal data-slot="dialog-portal" {...props} />;
 }
 
-function DialogClose({
-	asChild = false,
-	children,
-	render,
-	...props
-}: DialogPrimitive.Close.Props & { asChild?: boolean }) {
-	const resolved = resolveAsChild(asChild, children, render);
-	return (
-		<DialogPrimitive.Close
-			data-slot="dialog-close"
-			render={resolved.render}
-			{...props}
-		>
-			{resolved.children}
-		</DialogPrimitive.Close>
-	);
-}
-
 function DialogOverlay({
 	className,
 	...props
@@ -166,7 +148,6 @@ function DialogDescription({
 
 export {
 	Dialog,
-	DialogClose,
 	DialogContent,
 	DialogDescription,
 	DialogFooter,