Share page-check helpers in tests/page_check_common.py

MODES, TEST_FILL, FAKE_BRIDGE, the stub loader, the page opener and the no-AI case list now live in one place; sample_data and push move to tests/conftest.py.

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

tests/page_check/test_bot_run.py

@@ -6,7 +6,7 @@ import re
 from pathlib import Path
 
 import pytest
-from conftest import WIRED
+from page_check_common import WIRED
 from playwright.sync_api import expect
 from test_contract import colour_of, kpi, open_tab