Fix case-study share chrome, hero lockup width, and copy confirmation in the share dialog.

Marketing pages omitted create-flow nav copy, so Share rendered as a translation key; the case-study banner squeezed hero text to the thumbnail width; Copy link had no hover or copied state.

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

lib/propNormalization.ts

@@ -119,7 +119,11 @@ export type HeaderLockupPaletteValue =
 export const TEXT_INPUT_SIZE_OPTIONS = ["small", "medium"] as const;
 export type TextInputSizeValue = (typeof TEXT_INPUT_SIZE_OPTIONS)[number];
 
-export const CONTENT_CONTAINER_SIZE_OPTIONS = ["xs", "responsive"] as const;
+export const CONTENT_CONTAINER_SIZE_OPTIONS = [
+  "xs",
+  "responsive",
+  "useCase",
+] as const;
 export type ContentContainerSizeValue =
   (typeof CONTENT_CONTAINER_SIZE_OPTIONS)[number];