T-374 Remove deprecated NumerAPI round multiplier projections

[numerai-hosted-agent-bot]

Summary

• remove the six deprecated Corr/MMC compatibility projections from list_rounds()
• retain the full exact-identity roundScoreConfigs surface for Classic, Signals, and Crypto
• remove compatibility-only projection code/tests and update NumerAPI migration docs and changelog

Ownership

This is an official-client consumer cutover. Publishing a client that stops reading compatibility fields is a prerequisite for the scheduled server-field removal and may happen earlier.

This PR merged into preview. The final NumerAPI release and monorepo version/pin validation continue through PR #135 and T-374. The deprecated round_model_performances_v2 query remains a known gap and must stop requesting compatibility fields before T-374 closes.

Validation

• full NumerAPI tests and Ruff checks
• documentation build
• Classic, Signals, and Crypto exact-identity coverage

Linear: T-374

[ndharasz]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Breezy!

Reviewed commit: 7e91c46a25

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[numerai-hosted-agent-bot]

Release blocker found while updating T-469: tag 3.0.0.dev0 points to a35dbddf, whose setup.py sets numerapi_version = "3.0.0". The tag workflow will therefore build stable 3.0.0, while the requested 3.0.0.dev0 artifact is not available on PyPI. Please correct the package version/tag before publication (or explicitly revise the release plan); monorepo lock/pin updates cannot complete until the requested artifact exists. The August 28 stable-release gate remains recorded on monorepo PR #1142.