style: apply prettier across fork files

check:prettier was not part of my gate routine, so formatting drift accumulated
across the session's touched files (and a few older ones). Run prettier --write
to bring the repo back to 'All matched files use Prettier code style!'.
Formatting only — no logic changes. tsc/tests/build all green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/components/editor/output.test.ts

@@ -7,8 +7,7 @@ import { BlockType } from './types';
 // Loose Slate node builders for the test.
 const txt = (text: string, marks: Record<string, unknown> = {}) =>
   ({ text, ...marks }) as unknown as Descendant;
-const el = (type: BlockType, children: unknown[]) =>
-  ({ type, children }) as unknown as Descendant;
+const el = (type: BlockType, children: unknown[]) => ({ type, children }) as unknown as Descendant;
 
 const OPTS = {
   allowTextFormatting: true,