feat: move step-ca into a plugin (C4)

src/ui/sidebar/HostEditor.tsx

@@ -88,7 +88,6 @@ import { useSshAuthEditors } from "@/plugin-host/auth-registry";
 import { useSshAuthProviders } from "@/hooks/useSshAuthProviders";
 import { SshAuthProviderFields } from "./SshAuthProviderFields";
 import type { PluginSettingsField } from "@termix/plugin-sdk/manifest";
-import { ensureLegacyAuthUI } from "@/auth/legacy-auth-ui";
 import { PluginComponent } from "@/plugin-host/component-registry";
 import {
   toCredentialOption,
@@ -97,8 +96,6 @@ import {
 
 const CUSTOM_FONT_OPTION = "__custom__";
 
-ensureLegacyAuthUI();
-
 export function HostEditor({
   host,
   activeTab,