Add MCP codex-reply Support for Resuming Conversations from Rollout Files

What feature would you like to see?

I’d like to resume an existing Codex conversation via the MCP interface the same way the CLI already allows with codex resume <sessionId>.

Today the codex-reply MCP tool only succeeds if the conversation is still resident in the server’s in-memory ConversationManager. If the CLI has exited
—or if I start a fresh npx codex mcp-server—that map is empty, so codex-reply immediately returns:

Session not found for conversation_id: <uuid>

The rollout JSONL file is present on disk (e.g. ~/.codex/sessions/2025/11/03/rollout-...-019a4af1-f34f-7380-9133-6d1479737864.jsonl), and the CLI is able to hydrate it with codex resume 019a4af1-f34f-7380-9133-6d1479737864. The MCP server never exposes that resume path, so there’s no way for external integrations to continue a halted session.

Additional information

_No response_