Plan: Fix S1 test API response nesting bug

Goal

Fix test_s1_agents.py TC6: API response response field is nested under data, not at top level.

Files

• test_s1_agents.py — line 152: body.get("response") → body.get("data", {}).get("response")

Verification

• python3 test_s1_agents.py → 6/6 PASS
• python3 test_smoke.py → 8/8 PASS