Preserve OCR line breaks in markdown preview

app.py

@@ -205,7 +205,7 @@ def to_math_html(text: str) -> str:
     text = re.sub(r'\\\((.+?)\\\)', inline_math, text)
 
     # Run markdown on text that now contains only safe placeholder tokens
-    html = md_lib.markdown(text, extensions=['tables', 'fenced_code', 'sane_lists'])
+    html = md_lib.markdown(text, extensions=['tables', 'fenced_code', 'sane_lists', 'nl2br'])
 
     # Protect rendered code/pre blocks so placeholder swap never mutates literal code.
     protected_blocks: dict[str, str] = {}