Artifact: First Tool Call Is a Read

A tool-call log whose first logged action is a file read, before any write -- exercises co-07.

1. read_file(path="src/orders/discount.py")
2. read_file(path="tests/test_discount.py")
3. edit_file(path="src/orders/discount.py", diff="+  cap = min(cap, 500)")
4. run_shell(command="pytest tests/test_discount.py -q")

Verify: entry 1 is read_file, and both write-capable entries (edit_file at position 3, run_shell at position 4) occur strictly after it in the log -- satisfying ex-09's rule that the read precedes any write in the tool-call log.