AI sections fall back to fetch with no Qt bridge, for non-React web frontends

ai_sections.html fetches {API_BASE}+path when window.qt is absent; a page-check case routes those requests to server_stub.dispatch(). AI SKILL.md step 6 and frontend.md send plain-HTML/Vue/Angular/Svelte projects to it.

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

tests/page_check_common.py

@@ -63,13 +63,15 @@ def push_to(pg, event, data):
     pg.evaluate("([event, data]) => window.__pyMsg(JSON.stringify({event, data}))", [event, data])
 
 
-def open_page(browser, url, mode, init_script, expose=None):
+def open_page(browser, url, mode, init_script, expose=None, route=None):
     """Generator for a `page` fixture: opens url in one mode, signs in through a login
     section if the page has one, switches to dark, and fails on any page script error."""
     width, height, dark = MODES[mode]
     ctx = browser.new_context(viewport={"width": width, "height": height})
     if expose:
         ctx.expose_function(*expose)
+    if route:
+        ctx.route(*route)
     ctx.add_init_script(init_script)
     pg = ctx.new_page()
     pg.set_default_timeout(5000)