get_page() out-of-range/negative wrap reset to page 0 but returned pages[0] (a single item) even with per_page>1, mis-shaping the page downstream; it now reroutes through get_page(0) so the normal slice logic applies. cache shorter than max_pages now raises ValueError at construction instead of an IndexError when the cache button is clicked on a later page.
Signed-off-by: disqualifier <dev@disqualifier.me>
empty pages gave max_pages=0; get_page(0)/start() then IndexError'd on self.pages[0].
guard in __init__ with a clear ValueError instead of a deferred crash at render.
verified: ButtonPaginator([]) -> ValueError; non-empty and single-page intact.
Signed-off-by: disqualifier <dev@disqualifier.me>
