exec via `mise exec "$package"` so the tool resolves from mise's
install dir instead of by name through PATH. Previously `exec "$bin"`
could re-find the wrapper itself when ~/.local/bin precedes mise's
install path (e.g. when starship/zoxide clobber mise's PROMPT_COMMAND
hook, #3685), recursing forever. Scoping to $package keeps lazy install
and avoids leaking other runtimes into PATH.
husamemadH