feat(webhooks): add notification management API + one-click Sofarr webhook setup (Phase 3)

.env.sample

@@ -29,6 +29,12 @@ COOKIE_SECRET=your-cookie-secret-here
 # Generate with: openssl rand -hex 32
 SOFARR_WEBHOOK_SECRET=your-webhook-secret-here
 
+# Public base URL of Sofarr (for webhook configuration)
+# Required for the one-click webhook setup endpoints
+# Sonarr/Radarr need this URL to know where to send webhook events
+# Example: https://sofarr.example.com or https://192.168.1.100:3001
+SOFARR_BASE_URL=https://your-sofarr-url
+
 # =============================================================================
 # TLS / HTTPS
 # =============================================================================