Reserve the locale param, carry it on breadcrumbs, translate the permissions detail view

src/ui/list-query.test.ts

@@ -51,3 +51,8 @@ test("parseListQuery honours custom reserved names and page-size bounds", () =>
   assert.equal(parseListQuery("?n=999", { maxPageSize: 50, pageSizeParam: "n" }).pageSize, 50);
   assert.deepEqual(parseListQuery("?q=hi", { qParam: "search" }).filters, { q: ["hi"] });
 });
+
+test("`locale` is the host's, not a filter — every localized list link carries it", () => {
+  const query = parseListQuery("/admin/users?locale=sv-SE&status=active");
+  assert.deepEqual(Object.keys(query.filters), ["status"]);
+});

src/ui/list-query.ts

@@ -31,7 +31,9 @@ export function parseListQuery(url: URL | URLSearchParams | string, options: Lis
   const sortParam = options.sortParam ?? "sort";
   const pageParam = options.pageParam ?? "page";
   const pageSizeParam = options.pageSizeParam ?? "pageSize";
-  const reserved = new Set([pageParam, pageSizeParam, qParam, sortParam]);
+  // `locale` is host-owned (README → Languages): every list link and both GET forms carry it, so
+  // without this it would arrive as a phantom filter on every localized list page.
+  const reserved = new Set([pageParam, pageSizeParam, qParam, sortParam, "locale"]);
 
   const filters: Record<string, string[]> = {};
   for (const key of new Set(params.keys())) {