refactor: use the library's detector instead of hand-rolled selectors

detect_cloudflare_challenge(page, 'interstitial') matches the challenge on
the page and stops matching once it clears, measured on ext.to (True then
False), and on yggtorrent, nowsecure.nl and google.com, none of which carry
a /cdn-cgi/challenge-platform/ script when cleared. So the custom marker set
was unnecessary.

The turnstile variant is not usable for this: nowsecure.nl embeds turnstile
scripts on its normal page, so it reports a challenge even when cleared.

Also adds PlaywrightTimeoutError to the retryable set. It is a different
class from the builtin TimeoutError -- playwright's derives from its own
Error -- so a Playwright timeout inside the solver escaped the loop and
returned 408 without retrying.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TDMac4vGGcBhoUB5V6bvFK

src/endpoints.py

@@ -8,7 +8,6 @@ from typing import Annotated
 
 from fastapi import APIRouter, Depends, HTTPException
 from fastapi.responses import RedirectResponse
-from playwright.async_api import Page
 from playwright.async_api import TimeoutError as PlaywrightTimeoutError
 from playwright_captcha import CaptchaType
 from playwright_captcha.solvers.click.cloudflare.utils.detection import (
@@ -34,11 +33,6 @@ router = APIRouter()
 
 BrowserDep = Annotated[BrowserDepClass, Depends(get_browser)]
 
-CHALLENGE_MARKERS = (
-    'script[src*="/cdn-cgi/challenge-platform/"][src*="chl_page"], '
-    "#challenge-error-text, #challenge-running, #challenge-stage"
-)
-
 
 @router.get("/", include_in_schema=False)
 def read_root():
@@ -153,7 +147,12 @@ async def _solve_challenge(dep: BrowserDep, timer: TimeoutTimer) -> None:
     """Attempt to solve a detected Cloudflare interstitial challenge."""
     logger.info("Challenge detected, attempting to solve...")
     while timer.remaining() > 0:
-        with suppress(TimeoutError, CaptchaDetectionError, CaptchaSolvingError):
+        with suppress(
+            TimeoutError,
+            PlaywrightTimeoutError,
+            CaptchaDetectionError,
+            CaptchaSolvingError,
+        ):
             await wait_for(
                 dep.solver.solve_captcha(  # pyright: ignore[reportUnknownMemberType,reportUnknownArgumentType]
                     captcha_container=dep.page,
@@ -164,7 +163,7 @@ async def _solve_challenge(dep: BrowserDep, timer: TimeoutTimer) -> None:
                 timeout=min(15, timer.remaining()),
             )
 
-        if not await _challenge_visible(dep.page):
+        if not await detect_cloudflare_challenge(dep.page, "interstitial"):
             logger.debug("Challenge solved successfully.")
             return
 
@@ -172,14 +171,6 @@ async def _solve_challenge(dep: BrowserDep, timer: TimeoutTimer) -> None:
     raise TimeoutError(message)
 
 
-async def _challenge_visible(page: Page) -> bool:
-    """Report whether an unsolved challenge is still on the page."""
-    try:
-        return await page.locator(CHALLENGE_MARKERS).count() > 0
-    except Exception:
-        return False
-
-
 async def _wait_for_networkidle(dep: BrowserDep, timer: TimeoutTimer) -> None:
     """Wait for network idle, tolerating post-DOM-load stalls."""
     try:

tests/main_test.py

@@ -7,6 +7,9 @@ import httpx2
 import pytest
 from fastapi import HTTPException
 from playwright.async_api import TimeoutError as PlaywrightTimeoutError
+from playwright_captcha.solvers.click.cloudflare.utils.detection import (
+    CF_INTERSTITIAL_INDICATORS_SELECTORS,
+)
 from playwright_captcha.utils.exceptions import (
     CaptchaDetectionError,
     CaptchaSolvingError,
@@ -14,7 +17,7 @@ from playwright_captcha.utils.exceptions import (
 from starlette.testclient import TestClient
 
 from main import app
-from src.endpoints import CHALLENGE_MARKERS, read_item
+from src.endpoints import read_item
 from src.models import LinkRequest
 from src.utils import BrowserDepClass
 
@@ -165,7 +168,7 @@ def fake_dep(
 
     def count_for(selector: str) -> int:
         """Answer the marker check from the script, else from `challenged`."""
-        if selector != CHALLENGE_MARKERS or not remaining:
+        if selector not in CF_INTERSTITIAL_INDICATORS_SELECTORS or not remaining:
             return 1 if challenged else 0
         return remaining.pop(0) if len(remaining) > 1 else remaining[0]