Fix grammar bracket detection: split on spaces too, not just slashes

_is_grammar_bracket_content now splits "no pl" into ["no", "pl"]
instead of treating it as single token "no pl".

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

klausur-service/backend/cv_ocr_engines.py

@@ -907,8 +907,9 @@ def _is_grammar_bracket_content(content: str) -> bool:
     if not content:
         return False
 
-    # Split on / for patterns like (about/of), (on/with)
-    tokens = [t.strip().lower() for t in content.split('/') if t.strip()]
+    # Split on / and spaces for patterns like (about/of), (no pl)
+    tokens = re.split(r'[/\s]+', content.strip().lower())
+    tokens = [t for t in tokens if t]
     if not tokens:
         return False