Fix: Correct Mermaid flowchart edge for poor_query_percentage calculation without NUMERIC cast

Author: myoshi2891

SQL/Leetcode/Basic select/1211. Queries Quality and Percentage/Claude Sonnet 4.6 Extended/Queries_Quality_and_Percentage_postgresql.md

@@ -238,7 +238,7 @@ flowchart TD
     A_F --> B
     B --> C & D
     C --> E
-    D --> E
+    D --> F
     E --> F
     F --> G