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/state/usePageTitle.ts

@@ -22,7 +22,8 @@ const RULES: TitleRule[] = [
   { match: (p) => p.startsWith('/calendar'), title: 'Calendar' },
   { match: (p) => p.startsWith('/contacts'), title: 'Contacts' },
   { match: (p) => p.startsWith('/app-store'), title: 'App store' },
-  { match: (p) => p.startsWith('/plugins'), title: 'Plugins' },
+  { match: (p) => p.startsWith('/marketplace'), title: 'Marketplace' },
+  { match: (p) => p.startsWith('/plugins'), title: 'Marketplace' },
   { match: (p) => p.startsWith('/photos'), title: 'Photos' },
   { match: (p) => p.startsWith('/jellyfin'), title: 'Video' },
   { match: (p) => p.startsWith('/soulseek'), title: 'Soulseek' },