Add test coverage for CMA upgradability across modules

Problem

compact-contracts has no tests covering how modules behave under Midnight's Contract Maintenance Authority (CMA) upgrade mechanism (VerifierKeyInsert, VerifierKeyRemove, ReplaceAuthority).

Every module makes implicit assumptions about what ledger state survives a verifier-key rotation — none are currently asserted.

Goal

Cover the following across Ownable, AccessControl, ZOwnablePK, Pausable, Initializable, FungibleToken, NonFungibleToken:

• State survival across VK rotation
• CMA rotation (including rotation to empty = freeze)
• Multi-version VK coexistence
• Empty-CMA immutability
• Initializable cannot be reset via upgrade (safety-critical)