# Task: Group and Aggregate Sales Data

You are given a CSV file at `workspace/sales.csv` with columns: `date`, `category`, `product`, `amount`.

## Requirements

1. Read `workspace/sales.csv`.
2. Group the data by `category`.
3. Sum the `amount` for each category.
4. Sort the results by `total_amount` in descending order.
5. Write the result to `workspace/summary.csv` with columns: `category`, `total_amount`.

## Output

Save the summary CSV to `workspace/summary.csv`.
