test(traefik): mount the plugin's routes in the route test (#5741)

#5741 "Traefik routers are graded against their own normal". CI run 9126:
the new route test got 404, because CI doesn't enable the Traefik plugin
(enabling it would start its scraper against the shared database). The test
now mounts traefik_bp on its own app, as plugin_manager.load_plugins does,
with the plugin.yaml scrape interval.

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

tests/integration/test_traefik_latest.py

@@ -225,6 +225,12 @@ def test_the_page_grades_a_router_against_its_normal_and_lists_its_anomalies(app
         return (rows.status_code, await rows.get_data(as_text=True),
                 widget.status_code, await widget.get_data(as_text=True))
 
+    # CI doesn't enable the plugin (it would start scraping), so mount its
+    # blueprint here the way plugin_manager.load_plugins does.
+    from plugins.traefik.routes import traefik_bp
+    app.register_blueprint(traefik_bp, url_prefix="/plugins/traefik")
+    app.config["PLUGINS"].setdefault("traefik", {"enabled": True, "scrape_interval_seconds": 60})
+
     rows_status, page, widget_status, widget = asyncio.run(go())
     assert rows_status == 200 and widget_status == 200
     assert "4xx 60.0% is usual 58.0% at this hour" in page          # healthy, and says why