implement game catalog vector MCP resolver

sql/adb/79_sg_game_catalog_vector.sql

@@ -56,3 +56,25 @@ COMMENT ON TABLE sg_game_catalog IS
 COMMENT ON COLUMN sg_game_catalog.embedding IS
   'Vector representation of game names and aliases; populated by the configured embedding job.';
 /
+
+CREATE OR REPLACE FUNCTION sg_game_catalog_search(
+  p_question IN CLOB,
+  p_top_k IN PLS_INTEGER DEFAULT 5
+) RETURN SYS_REFCURSOR AUTHID DEFINER IS
+  v_query VECTOR;
+  v_result SYS_REFCURSOR;
+BEGIN
+  v_query := DBMS_VECTOR.UTL_TO_EMBEDDING(
+    p_question,
+    JSON(sg_qa_vector_params('search_query'))
+  );
+  OPEN v_result FOR
+    SELECT game_key, game_id, game_prefix, game_nm, game_alias_nm,
+           VECTOR_DISTANCE(embedding, v_query, COSINE) AS cosine_distance
+      FROM sg_game_catalog
+     WHERE active_yn = 'Y' AND embedding IS NOT NULL
+     ORDER BY VECTOR_DISTANCE(embedding, v_query, COSINE), priority, game_key
+     FETCH FIRST LEAST(GREATEST(NVL(p_top_k, 5), 1), 20) ROWS ONLY;
+  RETURN v_result;
+END;
+/