[Feature] Add a file based session persistent client

[randombet]

Current ClaudeSDKClient is base on subprocess and once subprocess is dead or quit unexpectedly. We will lose the session info.
SessionPersistentClient leverages ClaudeSDKClient and auto save and persist session data on local file.

[dicksontsai]

Thanks for this PR. I think we should just build this resilience into the default ClaudeSDKClient itself by leveraging the resume option. That way, we can avoid having to duplicate the conversation history storage (once here, once within Claude Code)

[randombet]

Thanks for this PR. I think we should just build this resilience into the default ClaudeSDKClient itself by leveraging the resume option. That way, we can avoid having to duplicate the conversation history storage (once here, once within Claude Code)

By "once within Claude Code", you mean on the server side, right? In that case, we still need session info (e.g session id, cost etc) on client side. LMK what do you think? @dicksontsai