Add K8s deployment for OCI (aarch64) and make deploy/deploy-oci targets

- K8s manifests: namespace, PVC (local-path 2Gi), deployment, service, ingress
- Ingress: repo-vis.oci.euphon.net with Let's Encrypt TLS via traefik
- Cross-compile aarch64-unknown-linux-musl for OCI ARM64 host
- make deploy: local Docker (x86_64)
- make deploy-oci: SCP binary + web dist to OCI, native docker build, k3s import
- Dockerfile accepts MUSL_TARGET build arg for multi-arch support

k8s/deployment.yaml

@@ -0,0 +1,35 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: repo-vis
+  namespace: repo-vis
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: repo-vis
+  template:
+    metadata:
+      labels:
+        app: repo-vis
+    spec:
+      containers:
+        - name: repo-vis
+          image: repo-vis:latest
+          imagePullPolicy: Never
+          ports:
+            - containerPort: 8080
+          env:
+            - name: PORT
+              value: "8080"
+            - name: FRONTEND_DIR
+              value: "./web/dist"
+            - name: DATA_DIR
+              value: "/data"
+          volumeMounts:
+            - name: data
+              mountPath: /data
+      volumes:
+        - name: data
+          persistentVolumeClaim:
+            claimName: repo-vis-data