Track Modal routing version in calculate analytics

[anth-volk]

Fixes #1541

Summary

• add nullable requested_version and resolved_channel analytics fields for calculate request and variable rows
• pass Modal gateway routing metadata through internal worker dispatch metadata rather than trusting public request headers
• expose the new fields and filters in the calculate analytics endpoint and OpenAPI spec

Testing

• make format-check exits 0; local Docker daemon warning is printed by the Makefile preamble
• uv run pytest tests/unit/endpoints/test_analytics_endpoint.py tests/unit/endpoints/test_household.py tests/unit/modal_release/test_gateway.py tests/unit/modal_release/test_worker_dispatch.py tests/unit/data/test_alembic_migrations.py tests/unit/data/test_analytics_setup.py tests/unit/models/test_analytics_models.py

Notes

• Alembic revision was generated via uv run alembic revision --autogenerate -m "add calculate analytics routing version" against a disposable SQLite analytics DB, then renamed to the repo timestamp revision format.
• Older/direct/GCP-style requests without Modal dispatch metadata store null routing fields.