feat(execution): implement ERC-721 transfer with retry/skip/abort branch behavior

[rosspeili]

Summary

Implement NFT transfer flow with non-blocking partial failure behavior.

Why

ADR defines per-item retry/skip semantics to avoid deadlocks.

Scope

• safeTransferFrom execution path
• Retry counter and max-attempt handling
• Skip/abort branch behavior with events

Acceptance Criteria

• Failing NFT item can be skipped/retried per policy
• Unrelated items continue unless marked atomic
• Tests cover branch outcomes