Move K8s sidecar from testing/ to examples/

The K8s sidecar is a standalone example, not a test harness — it has
no CI integration unlike testing/sidecar/. Move it to examples/
alongside sidecar-nostr-relay/ where it belongs. Update internal path
references in Dockerfile, build.sh, and README.

examples/k8s-sidecar/scripts/build.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+# Build the FIPS Kubernetes sidecar Docker image.
+# The build happens entirely inside Docker (multi-arch friendly).
+# Usage: ./scripts/build.sh [--tag TAG] [-- <extra docker buildx args>]
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+DOCKER_DIR="$(cd "$SCRIPT_DIR/.." && pwd)"
+PROJECT_ROOT="$(cd "$DOCKER_DIR/../.." && pwd)"
+
+IMAGE_TAG="fips-k8s-sidecar:latest"
+while [[ $# -gt 0 ]]; do
+    case "$1" in
+        --tag) IMAGE_TAG="$2"; shift 2 ;;
+        --) shift; break ;;
+        *) echo "Unknown option: $1" >&2; exit 1 ;;
+    esac
+done
+
+if [ ! -f "$PROJECT_ROOT/Cargo.toml" ]; then
+    echo "Error: Cannot find Cargo.toml at $PROJECT_ROOT" >&2
+    echo "Expected layout: <project-root>/examples/k8s-sidecar/scripts/build.sh" >&2
+    exit 1
+fi
+
+echo "Building Docker image: $IMAGE_TAG"
+docker build \
+    -t "$IMAGE_TAG" \
+    -f "$DOCKER_DIR/Dockerfile" \
+    "$@" \
+    "$PROJECT_ROOT"
+
+echo ""
+echo "Done. Image: $IMAGE_TAG"
+echo ""
+echo "Push to your registry, then apply the example manifest:"
+echo "  kubectl apply -f examples/k8s-sidecar/pod.yaml"