Add simulator-validated NetSuite SuiteQL slice

[harrisonoconnorhover]

Summary

• replace the misleading NetSuite record-list example with a bounded SuiteQL customer extraction path
• add a stateful six-operation FastAPI simulator with synthetic fixtures and OAuth1 HMAC-SHA256 verification
• prove pagination, create/update/replay, monotonic watermarks, throttling, missing permissions, expired credentials, malformed responses, and malformed records
• add the customer staging model, tracked OpenAPI contract, and explicit validation boundaries

Validation

• uv run ruff check .
• uv run ruff format --check .
• uv run mypy src tests
• uv run pytest — 664 passed
• wheel and source-distribution build/inspection
• source-free wheel installation with the documented dev extra

Boundaries

This is simulator-validated, not NetSuite-validated. It is not part of the supported public 0.2.0 surface. A current OAuth2 setup and one authorized real-tenant acceptance remain gates for any future supported release.

No version bump, package publication, deployment, Terraform/GCP mutation, NetSuite tenant access, or support claim is included.