Explore agent activity ledger and coordination graph

[bglusman]

Summary

Explore a Calciforge-wide agent activity ledger / coordination graph: structured, searchable metadata for agent intent, decisions, actions, artifacts, outcomes, blockers, and handoffs.

Why

Plain logs are too flat, while prompt-only decision tracking is too cooperative. Agents need situational awareness across the system, and operators need independently captured evidence of what actually happened.

Initial scope

• Define a small versioned ActivityEvent schema.
• Emit JSONL events for inbound messages, agent dispatch, policy/tool decisions, artifacts, and final responses.
• Add read-only query by project/session/actor.
• Group events into task/activity chains with correlation IDs.
• Test session recovery from the ledger instead of raw logs.

Reference

• docs/roadmap/agent-activity-ledger.md