Add LocalChat component using useLocalChat hook that communicates with
the Hub via IPC (no Gateway required). Fix streamId extraction to use
event.message.id matching Hub behavior. Fix history to return raw
AgentMessageItem[] instead of flattened strings. Add exec approval
forwarding over IPC. Use conditional rendering for LocalChat to prevent
event leaking from remote sessions.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
