added fortran program summary test

crates/pi-ast/src/summary.rs

@@ -987,6 +987,19 @@ mod tests {
 		);
 	}
 
+	#[test]
+	fn summarizes_fortran_program() {
+		let result = summarize(
+			"program hello\n  print *, 'hi'\nend program hello\n",
+			"fixture.f90",
+		);
+
+		assert!(result.parsed);
+		assert_eq!(result.language.as_deref(), Some("fortran"));
+		assert!(!result.segments.is_empty());
+	}
+
+
 	#[test]
 	fn summarizes_emacs_lisp_defun_body() {
 		let code = "(defun greet (name)\n  \"Doc.\"\n  (let ((message (format \"Hello %s\" \