Normalize double-dash to single dash in title comparison

LaTeX uses '--' for an en-dash; Semantic Scholar stores a plain '-'.
Adding .replace("--", "-") before other normalization makes them match.

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

Author: monperrus

check_hallucinations/main.py

@@ -32,6 +32,7 @@ def _normalize_title(title):
         title.lower()
         .strip()
         .rstrip(".")
+        .replace("--", "-")
         .replace("\\$", "$")
         .replace("\\%", "%")
         .replace("\\&", "&")

test_normalize.py

@@ -24,3 +24,9 @@ def test_latex_dollar_escape():
     bib = r"Fixing 55 out of 105 bugs for \$8 each"
     ss  = "Fixing 55 out of 105 bugs for $8 each"
     assert _normalize_title(bib) == _normalize_title(ss)
+
+
+def test_double_dash_vs_single_dash():
+    bib = "DeepSeek-Coder: When the large language model meets programming -- the rise of code intelligence"
+    ss  = "DeepSeek-Coder: When the Large Language Model Meets Programming - The Rise of Code Intelligence"
+    assert _normalize_title(bib) == _normalize_title(ss)