Fix batch count showing 0 in generate command output

- Save original batch count before processing loop
- Use saved count in final output message
- Fixes issue #3: 'across 0 batches' bug

src/main.rs

@@ -333,7 +333,8 @@ async fn main() -> anyhow::Result<()> {
             clean_csv_file(input_path, &temp_cleaned_path)?;
 
             let mut batches = read_csv_file_by_batch(&temp_cleaned_path)?;
-            println!("Found {} batches in CSV", batches.len());
+            let batch_count = batches.len();
+            println!("Found {} batches in CSV", batch_count);
 
             let mut total_customers = 0usize;
             let generated_date = Utc::now().format("%Y-%m-%d %H:%M").to_string();
@@ -405,7 +406,7 @@ async fn main() -> anyhow::Result<()> {
             println!(
                 "\nGenerated {} customer invoices across {} batches in {:?}",
                 total_customers,
-                batches.len(),
+                batch_count,
                 base_output_dir
             );
         }