Kiosk start, offline and setup pages in the InfoFlow display style

Dark grey background, name top left, date and clock top right, a flat
panel with a blue top edge. The pages show the kiosk link (token masked)
and the management address; the clock code is shared in kiosk.js.

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

tests/test_agent.py

@@ -169,3 +169,12 @@ def test_devtools_down_is_reported(env):
     browser.down = True
     agent.tick()
     assert json.loads(paths.agent_state_file.read_text())["browser"] == "unreachable"
+
+
+def test_offline_page_never_receives_the_token(env, paths):
+    agent, browser, probe, _, _ = env
+    save_config(paths.config_file, {"url": "https://e.org/scherm?token=geheim123456"})
+    probe.ok, probe.reason = False, "Time-out"
+    agent.tick()
+    assert "offline.html" in browser.url
+    assert "geheim" not in browser.url and "3456" in browser.url