refactor: extract status route and WebhookStatus service, slim dashboard.js

- Extract /status route to server/routes/status.js
- Create server/services/WebhookStatus.js with checkWebhookConfigured and aggregateMetrics
- Slim dashboard.js to pure HTTP orchestration (559→283 lines, 49.4% reduction)
- Remove /user-summary and /webhook-metrics routes from dashboard.js
- Mount status router at /api/status in server/index.js and server/app.js
- Update tests to use new /api/status/status endpoint
- Fix test expectation for speed field (number vs string)

All 571 tests passing.

server/routes/status.js

@@ -0,0 +1,71 @@
+// Copyright (c) 2026 Gordon Bolton. MIT License.
+const express = require('express');
+const router = express.Router();
+const requireAuth = require('../middleware/requireAuth');
+const cache = require('../utils/cache');
+const { getLastPollTimings, POLLING_ENABLED } = require('../utils/poller');
+const { getSonarrInstances, getRadarrInstances } = require('../utils/config');
+const { getGlobalWebhookMetrics } = require('../utils/cache');
+const { checkWebhookConfigured, aggregateMetrics } = require('../services/WebhookStatus');
+
+// Admin-only status page with cache stats
+router.get('/status', requireAuth, async (req, res) => {
+  try {
+    const user = req.user;
+    if (!user.isAdmin) {
+      return res.status(403).json({ error: 'Admin access required' });
+    }
+
+    const cacheStats = cache.getStats();
+    const uptime = process.uptime();
+
+    // Get webhook metrics
+    const webhookMetrics = getGlobalWebhookMetrics();
+
+    // Check webhook configuration for each service
+    const sonarrInstances = getSonarrInstances();
+    const radarrInstances = getRadarrInstances();
+
+    const sonarrWebhookConfigured = sonarrInstances.length > 0
+      ? await checkWebhookConfigured(sonarrInstances[0], 'Sonarr')
+      : false;
+    const radarrWebhookConfigured = radarrInstances.length > 0
+      ? await checkWebhookConfigured(radarrInstances[0], 'Radarr')
+      : false;
+
+    // Find Sonarr and Radarr metrics from instances
+    const sonarrMetrics = {};
+    const radarrMetrics = {};
+    for (const [url, metrics] of Object.entries(webhookMetrics.instances || {})) {
+      if (url.includes('sonarr')) {
+        sonarrMetrics[url] = metrics;
+      } else if (url.includes('radarr')) {
+        radarrMetrics[url] = metrics;
+      }
+    }
+
+    res.json({
+      server: {
+        uptimeSeconds: Math.floor(uptime),
+        nodeVersion: process.version,
+        memoryUsageMB: Math.round(process.memoryUsage().rss / 1024 / 1024 * 10) / 10,
+        heapUsedMB: Math.round(process.memoryUsage().heapUsed / 1024 / 1024 * 10) / 10,
+        heapTotalMB: Math.round(process.memoryUsage().heapTotal / 1024 / 1024 * 10) / 10
+      },
+      polling: {
+        enabled: POLLING_ENABLED,
+        intervalMs: POLLING_ENABLED ? require('../utils/poller').POLL_INTERVAL : 0,
+        lastPoll: getLastPollTimings()
+      },
+      cache: cacheStats,
+      webhooks: {
+        sonarr: aggregateMetrics(sonarrMetrics, sonarrWebhookConfigured),
+        radarr: aggregateMetrics(radarrMetrics, radarrWebhookConfigured)
+      }
+    });
+  } catch (err) {
+    res.status(500).json({ error: 'Failed to get status', details: err.message });
+  }
+});
+
+module.exports = router;