Closes#519
The ACP protocol's tool_call updates only carry a display title (not a
structured tool name) and omit rawInput for polished tools, making the
reconstructed messages unusable for step read/show.
Changes:
- hermes.ts: storePromptResult reads ~/.hermes/sessions/session_{id}.json
via loadHermesSession() instead of using ACP-reconstructed messages
- acp-client.ts: strip message/tool-call collection logic, keep only
text chunk accumulation for final response extraction
- step.ts: TurnData gains role + toolCalls fields; formatTurnBody
renders them in step read markdown output
- README: document sessions.write_json_snapshots requirement