Add unit tests for channel utilities and configure testing environment

- Created a new test file `channels.test.ts` to cover utilities related to channel configurations and targets.
- Implemented tests for normalizing and grouping selected channels by type, as well as building channel targets from account data and cron history.
- Mocked necessary dependencies to isolate tests and ensure accurate results.
- Updated `vite.config.ts` to set up the testing environment with jsdom and enable global variables for tests.

electron/api/routes/gateway.ts

@@ -1,6 +1,19 @@
 import type { HostApiContext } from '../context';
 import type { NormalizedHostApiRequest } from '../route-utils';
 import { fail, ok } from '../route-utils';
+import { buildGatewayDiagnosticsSummary } from '../../gateway/diagnostics';
+import { listAgentsSnapshot } from '../../utils/agent-config';
+import { listSelectedChannelAccountGroups } from '../../utils/channels';
+
+function buildChannelGroups(ctx: HostApiContext) {
+  const accounts = ctx.providerApiService
+    .getAccounts()
+    .filter((account) => account.enabled !== false);
+  const defaultAccountId = ctx.providerApiService.getDefault().accountId;
+  const snapshot = listAgentsSnapshot(accounts, defaultAccountId);
+
+  return listSelectedChannelAccountGroups(snapshot);
+}
 
 export async function handleGatewayRoutes(
   request: NormalizedHostApiRequest,
@@ -9,21 +22,31 @@ export async function handleGatewayRoutes(
   const { pathname, method } = request;
 
   if (pathname === '/api/app/gateway-info' && method === 'GET') {
-    const status = ctx.gatewayManager.getStatus();
+    const health = await ctx.gatewayManager.checkHealth();
+    const summary = buildGatewayDiagnosticsSummary(health, buildChannelGroups(ctx));
     return ok({
       transport: 'ipc-bridge',
       rpcChannel: 'gateway:rpc',
       eventChannel: 'gateway:event',
-      ...status,
+      ...health,
+      summary,
     });
   }
 
   if (pathname === '/api/gateway/status' && method === 'GET') {
-    return ok(ctx.gatewayManager.getStatus());
+    const status = await ctx.gatewayManager.checkHealth();
+    return ok({
+      ...status,
+      summary: buildGatewayDiagnosticsSummary(status, buildChannelGroups(ctx)),
+    });
   }
 
   if (pathname === '/api/gateway/health' && method === 'GET') {
-    return ok(await ctx.gatewayManager.checkHealth());
+    const health = await ctx.gatewayManager.checkHealth();
+    return ok({
+      ...health,
+      summary: buildGatewayDiagnosticsSummary(health, buildChannelGroups(ctx)),
+    });
   }
 
   if (pathname === '/api/gateway/start' && method === 'POST') {