refactor: Integrate summary search into dropdown and fix hierarchical mode

Previously created a separate page for summary search, which was redundant since hierarchical mode already demonstrates the summary→chunk pattern. Refactored to integrate summary-only mode as a dropdown option in the main search interface, reducing code duplication by ~370 lines.

Also fixed critical bug in hierarchical search where return_properties excluded the nested "document" object, causing source_id to be empty and all sections to be filtered out. Solution: removed return_properties to let Weaviate return all properties including nested objects.

All 4 search modes now functional:
- Auto-detection (default)
- Simple chunks (10% visibility)
- Hierarchical summary→chunks (variable)
- Summary-only (90% visibility)

Tests: 14/14 passed for dropdown integration, hierarchical mode confirmed working with 13 passages across 4 section groups.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

generations/library_rag/test_hierarchical_fix.py

@@ -0,0 +1,94 @@
+"""Test hierarchical search mode after fix."""
+
+import requests
+import sys
+import io
+from bs4 import BeautifulSoup
+
+# Fix Windows encoding
+if sys.platform == "win32":
+    sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8')
+    sys.stderr = io.TextIOWrapper(sys.stderr.buffer, encoding='utf-8')
+
+BASE_URL = "http://localhost:5000"
+
+def test_hierarchical_mode():
+    """Test hierarchical search mode."""
+    print("=" * 80)
+    print("TEST MODE HIÉRARCHIQUE APRÈS CORRECTION")
+    print("=" * 80)
+    print()
+
+    query = "What is the Turing test?"
+    print(f"Query: {query}")
+    print(f"Mode: hierarchical")
+    print("-" * 80)
+
+    try:
+        response = requests.get(
+            f"{BASE_URL}/search",
+            params={"q": query, "mode": "hierarchical", "limit": 5, "sections_limit": 3},
+            timeout=10
+        )
+
+        if response.status_code != 200:
+            print(f"❌ HTTP Error: {response.status_code}")
+            return
+
+        html = response.text
+
+        # Check if hierarchical mode is active
+        if "hiérarchique" in html.lower():
+            print("✅ Mode hiérarchique détecté")
+        else:
+            print("❌ Mode hiérarchique non détecté")
+
+        # Check for results
+        if "Aucun résultat" in html:
+            print("❌ Aucun résultat trouvé")
+            print()
+
+            # Check for fallback reason
+            if "fallback" in html.lower():
+                print("Raison de fallback présente dans la réponse")
+
+            # Print some debug info
+            if "passage" in html.lower():
+                print("Le mot 'passage' est présent")
+            if "section" in html.lower():
+                print("Le mot 'section' est présent")
+
+            return
+
+        # Count passages
+        passage_count = html.count("passage-card") + html.count("chunk-item")
+        print(f"✅ Nombre de cartes de passage trouvées: {passage_count}")
+
+        # Count sections
+        section_count = html.count("section-group")
+        print(f"✅ Nombre de groupes de sections: {section_count}")
+
+        # Check for section headers
+        if "section-header" in html:
+            print("✅ Headers de section présents")
+
+        # Check for Summary text
+        if "summary-text" in html or "Résumé" in html:
+            print("✅ Textes de résumé présents")
+
+        # Check for concepts
+        if "Concepts" in html or "concepts" in html:
+            print("✅ Concepts affichés")
+
+        print()
+        print("=" * 80)
+        print("RÉSULTAT: Mode hiérarchique fonctionne!" if passage_count > 0 else "PROBLÈME: Aucun passage trouvé")
+        print("=" * 80)
+
+    except Exception as e:
+        print(f"❌ ERROR: {e}")
+        import traceback
+        traceback.print_exc()
+
+if __name__ == "__main__":
+    test_hierarchical_mode()