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/api/plugins-api.ts

@@ -0,0 +1,38 @@
+import { rbacApi } from "@/main-axios";
+
+export interface PluginTabContribution {
+  id: string;
+  titleKey: string;
+  icon: string;
+  openFrom: string[];
+}
+
+export interface PluginContributions {
+  tabs?: PluginTabContribution[];
+}
+
+export interface PluginSummary {
+  id: string;
+  name: string;
+  version: string;
+  tier: string;
+  source: string;
+  enabled: boolean;
+  runtimeState: string;
+  lastError: string | null;
+  contributes: PluginContributions | null;
+}
+
+export async function getPlugins(): Promise<PluginSummary[]> {
+  const response = await rbacApi.get("/plugins");
+  return Array.isArray(response.data) ? response.data : [];
+}
+
+export async function setPluginEnabled(
+  pluginId: string,
+  enabled: boolean,
+): Promise<void> {
+  await rbacApi.patch(`/plugins/${encodeURIComponent(pluginId)}/state`, {
+    enabled,
+  });
+}