T5: Add serialize_actor method to TraceBook module

[dpaluy]

Task Details

Priority: p1 | Story Points: 2 | Group: B (Core Infrastructure)
Depends on: T4

Files

• lib/tracebook.rb

Acceptance Criteria

• serialize_actor extracts GlobalID or type/id tuple
• Handles nil actor gracefully
• Returns empty hash for non-serializable actors

Context

Part of PII Redaction Architecture Refactor - Phase 1: Core Infrastructure

See full plan: docs/plans/260106-02b-pii-redaction-architecture.md