test: Implement test_parse_multiple_filters test case

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/parser/filter_parser.rs

@@ -121,4 +121,11 @@ mod tests {
     
     #[test]
     fn test_parse_multiple_filters() {
-        let result =
+        let result = parse_filter_string("head_lines(10)|grep(pattern=\"error\")").unwrap();
+        assert_eq!(result.len(), 2);
+        assert_eq!(result[0].name, "head_lines");
+        assert_eq!(result[0].options["head_lines"], 10);
+        assert_eq!(result[1].name, "grep");
+        assert_eq!(result[1].options["pattern"], "error");
+    }
+}