Prepare TF-SDK 2.0.0rc4 candidate

Prepares a fresh 2.0.0rc4 candidate from the integrated develop baseline.

Updates package metadata and the CI release example. Runtime code, contracts and dependencies remain unchanged.

The protected candidate tag must run the Python matrix, dependency audit and SRM consumer checks before manual publication of the tested wheel and sdist. Final 2.0.0 publication remains a separate coordinated step.