feat: OCI deployment — Terraform VM + OKE stacks, OCIR, K8s manifests

- terraform-vm/: ARM VM (A1.Flex Free Tier), Docker Compose, Block Volume, LB+WAF+SSL
- terraform-oke/: OKE cluster (3 nodes Intel), NodePort, LB+WAF+SSL
- k8s/: namespace, deployments, services, PVC, secrets, configmap
- Dockerfile.frontend: self-contained nginx+dist image
- push-images.sh: multi-arch build (amd64+arm64) + push to OCIR
- dns.tf: conditional OCI DNS Zone + A record (when domain available)
- Both stacks 100% independent, no shared modules
- .gitignore: terraform state, .terraform/, *.tfvars

deploy/Dockerfile.frontend

@@ -0,0 +1,6 @@
+FROM nginx:alpine
+RUN rm -rf /usr/share/nginx/html/*
+COPY frontend-react/dist /usr/share/nginx/html/app
+COPY nginx/default.conf /etc/nginx/conf.d/default.conf
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]