the plugins screen becomes /marketplace

`/plugins` redirects rather than 404s: the word is in the dock, in the docs and in
whatever anyone bookmarked, and a route that worked yesterday returning nothing
reads as the feature having been removed. The API keeps its name — only the screen
moved — so the permission entry lists both paths, because a client-side redirect
is still a route that has to resolve before it can send anyone anywhere.

Also: the fetch stubs in marketplace.test.ts needed `as unknown as typeof fetch`.
Bun's `typeof fetch` carries `preconnect`, so a bare stub is not assignable —
tests passed while tsgo did not, which is the wrong way round to find out.

tsgo clean, frontend builds, 873 pass / 7 fail unchanged.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/apps/officer-web/Screens/Dashboard/Layout/Dock.tsx

@@ -186,7 +186,7 @@ export const CORE_DOCK_ITEMS: DockItem[] = [
   // things that disappears when uninstalled.
   { label: 'App store', to: '/app-store', icon: Store, color: '#64748b' },
   // Core, not contributed by a plugin: this is the screen that installs them, so it cannot arrive with one.
-  { label: 'Plugins', to: '/plugins', icon: Puzzle, color: '#94a3b8' },
+  { label: 'Marketplace', to: '/marketplace', icon: Puzzle, color: '#94a3b8' },
 ];
 
 /**