Move getCachedSessionId/setCachedSessionId from workflow-agent-hermes
into workflow-agent-kit so all agent adapters can share the same
session cache logic.
Add cross-process session resume to workflow-agent-claude-code:
on re-entry (isFirstVisit=false), look up the cached sessionId and
use 'claude --resume' to continue with full conversation history.
Cache file renamed from hermes-sessions.json to agent-sessions.json
to reflect its shared nature.
Refs #418
xiaoju
1afaeacd57