Store provider_name/model on sessions (SQLite migrate); restore on resume and persist on create//model//provider. Startup prefers session selection over re-asking. ask/choose and provider/model pick use readline with Tab completion when available.
Add MemoryStore rename/delete with explicit message cleanup. Slash commands /rename, /delete (confirm), /export md|json write transcripts from DB; deleting the current session starts a fresh empty one.