Implement renounce operations in the Stellar access control adapter

[pasevin]

Summary

The OpenZeppelin Stellar contracts (stellar-contracts) support three renounce operations that are not yet implemented in the Stellar adapter (adapter-stellar):

On-chain function	Contract	Stellar adapter status
renounce_ownership(e)	Ownable	Feature flag detected, but no action assembly or service method
renounce_role(e, role, caller)	AccessControl	hasRenounceRole hardcoded to false — no action or service method
renounce_admin(e)	AccessControl	No shared interface capability — not wired at all

The EVM adapter (adapter-evm-core) already implements renounceOwnership and renounceRole with full feature detection, action assembly, and service methods. The Stellar adapter should reach parity.

Context

• The EVM adapter was implemented in branch 011-evm-access-control.
• The Stellar feature-detection.ts already sets hasRenounceOwnership = true when the schema contains renounce_ownership, but the service has no corresponding method — clicking the UI button would throw "not supported by this adapter".
• hasRenounceRole is hardcoded to false with the comment "Stellar uses revokeRole for self-revocation", which is inaccurate — the on-chain contracts have a dedicated renounce_role function.

Tasks

1. renounceOwnership

• Add assembleRenounceOwnershipAction() in adapter-stellar/src/access-control/actions.ts — invoke renounce_ownership() with no args
• Add renounceOwnership() method on StellarAccessControlService
• Add tests

2. renounceRole

• Add assembleRenounceRoleAction() in adapter-stellar/src/access-control/actions.ts — invoke renounce_role(role, caller)
• Add renounceRole() method on StellarAccessControlService
• Update feature detection: derive hasRenounceRole from schema (check for renounce_role) instead of hardcoding false
• Add tests

3. renounceAdmin (optional / future)

• Evaluate whether to add a hasRenounceAdmin capability to the shared AccessControlCapabilities type
• If added, implement assembleRenounceAdminAction() and service method
• Note: no EVM equivalent exists — this would be Stellar-specific

References

• Stellar contracts source: stellar-contracts/packages/access/src/ownable/storage.rs and stellar-contracts/packages/access/src/access_control/storage.rs
• EVM adapter implementation: adapter-evm-core/src/access-control/actions.ts, adapter-evm-core/src/access-control/service.ts
• Shared types: ui-types/src/adapters/access-control.ts (AccessControlCapabilities)