Optional controlled-deployment adapter

Unreleased breaking change: the optional Pydantic adapter and the controlled-deployment extras are retired in the next Python minor release. The last published 0.7.0 packages still contain them. Remove imports of qgis_sdk.adapters.pydantic and qgis_sdk.adapters.pydantic_types and remove the extra from installation requirements. No drop-in replacement is provided for PydanticContractAdapter or SafeJsonInteger: migrate to supported SDK declarations and their validation where applicable, or explicitly implement, provision and test your own Pydantic integration. SDK contract integer limits remain available as qgis_sdk.models.MAX_SAFE_INTEGER.

This does not prevent a plugin from using a separately provisioned Pydantic package; it removes the SDK’s adapter and dependency extra. Historical release and qualification records below describe the old release, not current support. See decision-67.