feat: facette Extensions dans les facettes de recherche #157

backend/search.py

@@ -1327,6 +1327,7 @@ def advanced_search(
     scored_results: list[tuple[float, dict[str, Any]]] = []
     facet_tags: dict[str, int] = defaultdict(int)
     facet_vaults: dict[str, int] = defaultdict(int)
+    facet_extensions: dict[str, int] = defaultdict(int)
 
     # Pre-compute prefix expansions once per term (avoid repeated binary search)
     prefix_expansions: dict[str, list[str]] = {}
@@ -1426,6 +1427,11 @@ def advanced_search(
         facet_vaults[result["vault"]] = facet_vaults.get(result["vault"], 0) + 1
         for tag in result.get("tags", []):
             facet_tags[tag] = facet_tags.get(tag, 0) + 1
+        # Extension normalised without leading dot ("md", not ".md") so it can be
+        # fed back directly as the `ext:` query operator.
+        ext = str(result.get("extension") or "").lower().lstrip(".")
+        if ext:
+            facet_extensions[ext] = facet_extensions.get(ext, 0) + 1
 
     total = len(scored_results)
     page = scored_results[offset: offset + limit]
@@ -1439,6 +1445,7 @@ def advanced_search(
         "facets": {
             "tags": dict(sorted(facet_tags.items(), key=lambda x: -x[1])[:20]),
             "vaults": dict(sorted(facet_vaults.items(), key=lambda x: -x[1])),
+            "extensions": dict(sorted(facet_extensions.items(), key=lambda x: -x[1])),
         },
         "query_time_ms": elapsed_ms,
         "semantic_available": semantic_available,