feat(aula-14): adicionar Istio Traffic Splitting com canary deployment

- Instala Istio (base + istiod + ingressgateway)
- Configura Kiali e Jaeger para observabilidade
- Deploy de app-backend v1 e v2 com traffic splitting 90/10
- Integra com Victoria Metrics da aula-12
- Inclui teste-stress.sh para validar distribuição de tráfego
- Tráfego externo passa pelo Istio Gateway via NGINX Ingress

aula-14/k8s/deployment-v2.yaml

@@ -0,0 +1,53 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: app-backend-v2
+  namespace: istio
+  labels:
+    app: app-backend
+    version: v2
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: app-backend
+      version: v2
+  template:
+    metadata:
+      labels:
+        app: app-backend
+        version: v2
+    spec:
+      imagePullSecrets:
+        - name: regcred
+      containers:
+        - name: app-backend
+          image: ${REGISTRY_HOST}/${REGISTRY_PROJECT}/app-backend:v2
+          imagePullPolicy: Always
+          ports:
+            - containerPort: 3000
+          env:
+            - name: MAX_REQUESTS
+              value: "100"
+          resources:
+            requests:
+              memory: "64Mi"
+              cpu: "50m"
+            limits:
+              memory: "128Mi"
+              cpu: "100m"
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: 3000
+            initialDelaySeconds: 5
+            periodSeconds: 5
+            failureThreshold: 3
+          readinessProbe:
+            httpGet:
+              path: /health
+              port: 3000
+            initialDelaySeconds: 3
+            periodSeconds: 3
+            failureThreshold: 2
+      terminationGracePeriodSeconds: 10