Genuinely type composable any usages (useStepper/useStorage/useForm/
createEventHook/useSorted/etc.) as proper generics/unknown; keep idiomatic
any-function and overload-impl signatures with comments; skipped test -> .todo.
Setting a custom property to 'initial' (a CSS-wide keyword) computes to the guaranteed-invalid value, so getComputedStyle returns '' — correct per spec and now implemented by jsdom 29 (the deps bump from jsdom 28). Use a normal token ('start') so the read returns the value.