chronicle-save valid kinds (CLI rejects 'decision', 'tool_result', 'error')

The chronicle-save CLI binary (Chronicle 2.0, local Postgres backend) rejects several kinds with Error: invalid event kind "decision". Workspace docs (e.g. AGENTS.md instructions) commonly list these kinds as valid: observation, error, decision, tool_result, plan. Three of those — error, decision, tool_result — are NOT accepted by the binary. Agents following stale docs hit the error mid-flush and have to retry every save with a remapped kind.