feat(config, i18n): add integration guide documentation page with multi-language support

Added new integration guide page accessible from config hub, providing SSO and wallet integration documentation for client engineering teams. Includes translations in English, Nepali, and Chinese. Refactored percentage conversion utilities across agent management modules to use consistent `percentValueToUi` function, removing deprecated `ratioToPercentUi` and `percentUiToRatio` helpers.

src/app/admin/docs/integration-guide/page.tsx

@@ -0,0 +1,18 @@
+import { AdminPermissionGate } from "@/components/admin/admin-permission-gate";
+import { ShellAuthGate } from "@/components/admin/auth-gate";
+import { IntegrationGuideScreen } from "@/modules/docs/integration-guide-screen";
+import { PRD_INTEGRATION_ACCESS_ANY } from "@/lib/admin-prd";
+import { buildPageMetadata } from "@/lib/page-metadata";
+import type { Metadata } from "next";
+
+export const metadata: Metadata = buildPageMetadata("config", "integrationGuide.title");
+
+export default function AdminIntegrationGuidePage(): React.ReactElement {
+  return (
+    <ShellAuthGate>
+      <AdminPermissionGate requiredAny={PRD_INTEGRATION_ACCESS_ANY}>
+        <IntegrationGuideScreen />
+      </AdminPermissionGate>
+    </ShellAuthGate>
+  );
+}