feat: ship the ssh terminal as a first-party in-process plugin

Adds a hardcoded process:transport-owner tier so the terminal can own its
WebSocket server and ssh2 clients, which cannot cross the worker boundary.

src/ui/sidebar/AdminSettingsPanel.tsx

@@ -94,6 +94,7 @@ import {
   type UserRole,
 } from "@/main-axios";
 import { type AdminSection, type Host } from "@/types/ui-types";
+import { AdminPluginsSection } from "./AdminPluginsSection";
 import {
   AdminRolesSection,
   AdminSessionsSection,
@@ -1496,6 +1497,11 @@ export function AdminSettingsPanel({
         users={users}
       />
 
+      <AdminPluginsSection
+        open={openSections.has("plugins")}
+        onToggle={() => toggle("plugins")}
+      />
+
       <AdminTouchInputSection
         open={openSections.has("touch-input")}
         onToggle={() => toggle("touch-input")}