Enforce certificate profile crypto constraints across all 5 issuance paths
(renewal, agent CSR, EST, SCEP). ValidateCSRAgainstProfile() rejects CSRs
with key algorithm/size that don't match profile rules. MaxTTL enforcement
caps certificate validity per issuer connector (Local CA, Vault, step-ca
enforce directly; ACME/DigiCert/Sectigo pass through). Key algorithm and
size are now persisted in certificate_versions for audit compliance.
16 new tests (12 service-layer + 4 Local CA connector). Removes hardcoded
version number from GUI sidebar. Documentation updated across architecture,
features, connectors, and README.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Shankar