feat: scaffold backend with FastAPI, config files, and health endpoint

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/config/services.yaml

@@ -0,0 +1,20 @@
+nodes:
+  - name: "Router Principal"
+    ip: "192.168.1.1"
+    username: "admin"
+    password: "admin"
+    icon: "router"
+    connections: []
+
+  - name: "Servidor Ejemplo"
+    ip: "192.168.1.10"
+    username: "root"
+    password: "password"
+    public_url: "https://ejemplo.com"
+    icon: "server"
+    connections: ["Router Principal"]
+
+network_scan:
+  enabled: true
+  subnet: "192.168.1.0/24"
+  interval_minutes: 10