retriever: prioritize keyword chunks

atlasbot/engine/answerer.py

@@ -1094,10 +1094,28 @@ def _select_chunks(
     selected: list[dict[str, Any]] = []
     head = chunks[0]
     selected.append(head)
+
+    keyword_hits: list[dict[str, Any]] = []
+    if keywords:
+        lowered = [kw.lower() for kw in keywords if isinstance(kw, str) and kw.strip()]
+        for item in ranked:
+            if item is head:
+                continue
+            text = str(item.get("text") or "").lower()
+            if any(kw in text for kw in lowered):
+                keyword_hits.append(item)
+
+    for item in keyword_hits:
+        if len(selected) >= plan.chunk_top:
+            return selected
+        if item in selected:
+            continue
+        selected.append(item)
+
     for item in ranked:
         if len(selected) >= plan.chunk_top:
             break
-        if item is head:
+        if item in selected:
             continue
         selected.append(item)
     return selected