feat(web): page-driven breadcrumb context + header render + objects wiring (#54)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/objects/objects-page.tsx

@@ -6,6 +6,7 @@ import { X } from "lucide-react";
 import { ObjectsTable } from "./objects-table";
 import { useMediaQuery } from "../lib/use-media-query";
 import { useDocumentTitle } from "../lib/use-document-title";
+import { useBreadcrumb } from "../shell/use-breadcrumb";
 import { PageTitle } from "@/components/ui/page-title";
 
 const ObjectDetailDrawer = lazy(() =>
@@ -26,6 +27,7 @@ export function ObjectsPage() {
   const isWide = useMediaQuery("(min-width: 1024px)");
 
   useDocumentTitle(t("nav.objects"));
+  useBreadcrumb([{ label: t("nav.objects") }]);
 
   const closeDetail = () => navigate(`/objects?${searchParams}`);