Restore QA single-newline rendering behavior

Code review flagged a UX regression after sanitizer refactor: assistant single newlines stopped rendering as hard breaks. Re-enable marked breaks mode in the shared QA renderer to preserve previous panel readability for streamed and lightly formatted answers.

Constraint: Keep sanitizer fix while matching prior QA markdown display behavior

Rejected: Add newline post-processing in QaPanel | duplicates renderer concern and increases drift risk

Confidence: high

Scope-risk: narrow

Directive: QA markdown display flags must be centralized in qaMarkdown.ts to keep streaming/final parity

Tested: npm run build (openless-all/app)

Not-tested: Manual visual QA panel check on desktop runtime

openless-all/app/src/lib/qaMarkdown.ts

@@ -59,6 +59,7 @@ export function renderQaMarkdown(markdown: string): string {
   return marked.parse(escaped, {
     async: false,
     gfm: true,
+    breaks: true,
     renderer: QA_MARKDOWN_RENDERER,
   }) as string;
 }