refactor: eliminate jscpd clones and boost tests

src/gateway/server.agent.gateway-server-agent-a.e2e.test.ts

@@ -3,6 +3,7 @@ import os from "node:os";
 import path from "node:path";
 import { afterAll, beforeAll, describe, expect, test, vi } from "vitest";
 import type { ChannelPlugin } from "../channels/plugins/types.js";
+import { createChannelTestPluginBase } from "../test-utils/channel-plugins.js";
 import { setRegistry } from "./server.agent.gateway-server-agent.mocks.js";
 import { createRegistry } from "./server.e2e-registry-helpers.js";
 import {
@@ -95,22 +96,15 @@ const createStubChannelPlugin = (params: {
   label: string;
   resolveAllowFrom?: (cfg: Record<string, unknown>) => string[];
 }): ChannelPlugin => ({
-  id: params.id,
-  meta: {
+  ...createChannelTestPluginBase({
     id: params.id,
     label: params.label,
-    selectionLabel: params.label,
-    docsPath: `/channels/${params.id}`,
-    blurb: "test stub.",
-  },
-  capabilities: { chatTypes: ["direct"] },
-  config: {
-    listAccountIds: () => ["default"],
-    resolveAccount: () => ({}),
-    resolveAllowFrom: params.resolveAllowFrom
-      ? ({ cfg }) => params.resolveAllowFrom?.(cfg as Record<string, unknown>) ?? []
-      : undefined,
-  },
+    config: {
+      resolveAllowFrom: params.resolveAllowFrom
+        ? ({ cfg }) => params.resolveAllowFrom?.(cfg as Record<string, unknown>) ?? []
+        : undefined,
+    },
+  }),
   outbound: {
     deliveryMode: "direct",
     resolveTarget: ({ to, allowFrom }) => {