No way to change /effort for the current session only — always overwrites the persisted default

\/effort <level>\ always writes \effortLevel\ to \~/.claude/settings.json\, changing the default for all future sessions, not just the current one. This seems related to #53331.

There's no way to temporarily raise effort for the rest of an in-progress conversation without permanently changing your saved default. The \--effort <level>\ CLI flag is session-only, but it must be set at launch — it can't be applied mid-session.

Request: Make \/effort <level>\ change the current session only by default (matching the \--effort\ flag's behavior), with an explicit opt-in (e.g. \/effort <level> --default\ or \/effort set-default <level>\) to persist it.