DataPrivacyFramework permission mutators lack authorization checks

[SashaMIT]

Summary

DataPrivacyFramework is the access-control store consulted by DataPrivacyFrameworkMpc (including op_decrypt) via onlyAllowedUserOperation. The constructor seeds the deployer with an "admin" permission, but every permission mutator is public/external with no gate:

• setPermission
• setAddressDefaultPermission
• setOperationDefaultPermission
• addAllowedOperation / removeAllowedOperation
• addRestrictedOperation / removeRestrictedOperation

Any address can therefore grant itself gated MPC operations (including decrypt) or erase an integrator's policy.

Proposed fix

Gate mutators with onlyAdmin requiring isOperationAllowed(msg.sender, "admin"), bootstrap constructor via an internal _setPermission, and mark mutators virtual for integrator overrides. Note: this is a potentially breaking change for anyone who relied on open mutators.

Happy to open a PR with regression tests (non-admin reverts).