fix(frontend): isolate administration rail from portal CSS

frontend/e2e/database-management-layout.spec.ts

@@ -426,12 +426,15 @@ test("context panels stay inside the manager and the Tables grid sits in a sideb
   const administrationPanel = adminNavigationRail.getByRole("region", { name: "Administration" });
   await expect(administrationPanel).toBeVisible();
   expect(await administrationPanel.locator(":scope > *").evaluateAll((elements) => elements.map((element) => (
-    element.getAttribute("role") === "separator" ? "separator" : element.textContent?.trim()
+    element.getAttribute("role") === "separator"
+      ? "separator"
+      : element.getAttribute("aria-label") ?? element.textContent?.trim()
   )))).toEqual([
     "Database management",
     "separator",
     "Workspace management",
     "Pi management",
+    "Workspace preprocessing",
   ]);
 
   await administration.click();