feat(gns2): mass-update all 30 agents with GNS-2 protocol
- 29 agents updated with GNS-2 checkpoint/event protocol
- 12 Tier 0 (leaf) agents: read checkpoint, write event footer, no cascade
- 17 Tier 1 (task) agents: read checkpoint, recommend next agent, no direct task calls
- 2 Tier 2 (meta) agents already updated: capability-analyst, agent-architect, evaluator
- All agents now include GNS_EVENT footer template in comments
- Frontmatter updated with '(GNS-2 Tier N)' classification
Scripts added:
- scripts/mass-update-gns-agents.py — idempotent mass updater
- scripts/validate-gns-agents.py — protocol checker
Refs: Milestone #67, Issues #99-#107
bd154f24d0