Gate, expense approver

A policy.yaml and twelve receipts (inbox/receipts.jsonl) used by CMA_gate_human_in_the_loop.py. The agent classifies each receipt against the policy with two custom tools: decide() for clear approves and rejects, escalate() for anything ambiguous.

The twelve receipts are designed to hit every branch of the policy: a handful that should auto-approve cleanly, one with no receipt image where the policy demands one, a couple in the manager-approval band, two over the threshold, one travel charge that always escalates regardless of amount, and one with a deliberately ambiguous category. A healthy run produces a mix of approve, reject, and escalated decisions, never all of one lane.