[KYC Agent] #11: End-to-end integration tests

[nagasatish007]

Parent: #434
Depends on: #444 (pipeline)

Goal

Write integration tests that run the full pipeline against all 50 synthetic customer fixtures and verify:

• Correct decisions (approve/escalate/reject matches expected)
• Governance audit trail is complete
• PII is never present in unredacted LLM context
• Budget is tracked correctly
• Performance: <500ms per onboarding (mock mode)

Deliverables

• tests/test_integration.py
• Tests all 50 fixtures
• Asserts governance decisions are recorded
• Asserts PII redaction works
• Asserts budget tracking

No API keys needed