fix: remediate audited defects (resolves #29, #30, #31, #32)

- Fix permanent qBittorrent fallback degradation by resetting fallback flags during group-by polling (resolves #29)
- Fix Ombi webhook key mismatch in status endpoint and test mocks (resolves #30)
- Prevent timingSafeEqual TypeErrors on multi-byte CSRF token length mismatches (resolves #31)
- Eliminate duplicate write stream on server.log by delegating to index.js console override (resolves #32)

server/routes/ombi.js

@@ -392,9 +392,9 @@ router.get('/webhook/status', requireAuth, async (req, res) => {
         requestProcessing: webhookConfig.enabled || false
       },
       stats: metrics ? {
-        eventsReceived: metrics.eventCount || 0,
+        eventsReceived: metrics.eventsReceived || 0,
         pollsSkipped: metrics.pollsSkipped || 0,
-        lastWebhookTimestamp: metrics.lastEventTimestamp || null
+        lastWebhookTimestamp: metrics.lastWebhookTimestamp || null
       } : null
     });
   } catch (error) {