dedup references and URL title correction

app.py

@@ -274,17 +274,24 @@ Answer:"""
                             # Only append references when the model actually answered
                             no_answer_phrase = "The provided context does not contain enough information to answer this question."
                             if no_answer_phrase not in response_text:
+                                # Deduplicate: one entry per unique source URL (or label)
+                                seen = {}
+                                for i, source_label in context_index_to_source.items():
+                                    url = context_index_to_url.get(i)
+                                    key = url or source_label
+                                    if key not in seen:
+                                        seen[key] = (source_label, url)
+
                                 ref_lines = [
                                     "",
                                     "---",
                                     "**References**",
                                 ]
-                                for i, source_label in context_index_to_source.items():
-                                    url = context_index_to_url.get(i)
+                                for idx, (key, (source_label, url)) in enumerate(seen.items(), 1):
                                     if url:
-                                        ref_lines.append(f"{i}. [{source_label}]({url})")
+                                        ref_lines.append(f"{idx}. [{source_label}]({url})")
                                     else:
-                                        ref_lines.append(f"{i}. {source_label}")
+                                        ref_lines.append(f"{idx}. {source_label}")
                                 response_text = response_text.rstrip() + "\n\n" + "\n".join(ref_lines)
                             return response_text
                         raise ValueError("Empty response from model")