fix: load plain-http URLs behind a Cloudflare challenge

Firefox's HTTPS-First mode upgrades an http:// navigation, sees the
challenge's 403 and falls back to http as a fresh navigation. That
aborts page.goto() with "interrupted by another navigation", so any
http:// URL to a challenged site failed before the solver could run.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/utils.py

@@ -102,6 +102,7 @@ async def get_browser(
             "devtools.jsonview.enabled": False,
             "browser.tabs.remote.useCrossOriginOpenerPolicy": False,
             "browser.tabs.remote.useCrossOriginEmbedderPolicy": False,
+            "dom.security.https_first": False,
         },
     ) as browser_raw:
         # InvisiblePlaywright yields a Browser instance

tests/main_test.py

@@ -25,6 +25,7 @@ test_websites = [
     "https://speed.cd/login",
     'https://www.yggtorrent.top/engine/search?do=search&order=desc&sort=publish_date&name="UNESCAPED"+"DOUBLEQUOTES"&category=2145',
     "https://1337x.to/home/",
+    "http://1337x.to/home/",
 ]