feat(timesheet): sort months ascending so newest is at bottom

src/timesheet/generator.rs

@@ -235,11 +235,11 @@ pub fn generate_report(
         }
     }
 
-    // Sort months in descending order (most recent first)
+    // Sort months in ascending order (oldest first, newest at bottom)
     month_reports.sort_by(|a, b| {
         let a_date = (a.year, a.month);
         let b_date = (b.year, b.month);
-        b_date.cmp(&a_date)
+        a_date.cmp(&b_date)
     });
 
     Ok(TimesheetReport::new()