Replace the system-curl SOCKS5 subprocess transport with the shared
BrowserFetcher (camoufox). camoufox's real-browser fingerprint is not
tarpitted by yandex and does not burn the mobile-proxy IP; raw system-curl
got the proxy IP flagged.
One BrowserFetcher is opened per scraper session in __aenter__ and reused
across all page fetches. _http_get now fetches via the browser, extracts the
gate-API JSON from camoufox's HTML <pre> wrapper, and returns it as the body
of a _CurlResponse (status 200 on success, 0 on fetch/extraction failure) so
all existing callers and the tarpit retry/rotate logic keep working unchanged.
URL building, _parse_gate_json, pagination, combos and field mapping are
untouched. Removed the dead curl subprocess constants/method.
