- Introduce the Agent domain model, run/workspace/checkpoint repositories,
and a file-backed workspace store with event journaling.
- Wire the runtime service into Tauri commands and expose the frontend Agent
API for starting, observing, cancelling, reading, and committing runs.
- Derive workspaces from stable chat identity while keeping each run isolated,
and make unsupported Phase 1 paths fail fast.
- Document the Agent architecture, API contract, workspace model, LLM gateway,
tool/MCP boundaries, and implementation plan.
