* add versioned root and intermediate CA profile documents
* extend the strict profile schema with closed certificate kinds
* package canonical built-in root and intermediate profiles
* enforce immutable import and explicit activation for CA profiles
* bind CA credentials to exact profile ID, version, and canonical hash
* resolve active profiles for root and intermediate issuance
* validate issuer-controlled CA requests before backend execution
* enforce complete CA DER and extension postconditions
* reject inactive, mismatched, and malicious profile/backend inputs
* preserve historical credential bindings across profile activation changes
* add root and intermediate profile version-switch coverage
BREAKING CHANGE: root and intermediate CA issuance now requires an explicitly imported and activated versioned CA profile.