refactor(poc-grpc): restructure project into modular 12-factor architecture with dedicated orchestrator and agent_node packages

feat(poc-grpc): implement Phase 4 Browser Pro features with Actor Threading and real-time event tunneling

feat(browser-skill): Implement Phase 4 Browser Automation foundations & fix GitBucket utility formatting

feat(distributed-agent): Refactor to Skill-Based Architecture, implement Robust Task Management & finalize Roadmap

feat(agent): support PERMISSIVE vs STRICT sandbox modes #7

feat(agent): complete phase 2 security, identity, and observability #6

feat(agent): implement phase 1 gRPC POC and update architecture docs #5