[test/otel/pernode] Add per-node + zero-step CRD E2E suite and EKS harness

[wenegiemepraise]

Summary

Add the test/otel/pernode integration suite plus a Terraform EKS harness that validates
the ServiceMonitor/PodMonitor scraping path end to end on a live cluster: per-node target
locality, zero-step CRD bundling, and Target Allocator resilience to missing CRDs.

What's included

Suite (test/otel/pernode/, build tag integration):

• per_node_test.go — every SM/PM series is node-local: target_node == @resource.k8s.node.name; targets span ≥2 nodes.
• crd_bundling_test.go — SM + PM CRDs are served/established after a plain chart install (harness never installs them separately).
• ta_resilience_test.go — TA Deployment Available, no CrashLoopBackOff, 0 restarts on a fresh cluster; and it actually discovers monitors.
• setup_test.go, k8s_helpers_test.go, metrics_test.go — shared clientset/ground-truth, CRD discovery, otelmetrics client bootstrap.
• resources/workload.yaml — sm-app/pm-app workloads + SM/PM with the target_node relabel + load generator.

Harness (terraform/eks/daemon/otel-pernode/): provisions EKS, installs the chart with the
per-node-capable operator/TA images, applies the workloads, and runs the suite. Because it
exercises unreleased code it takes operator_image_*, ta_image, helm_chart_repo/branch vars.

Verification method (per-node)

target_node             = scraped POD's node   (SM/PM relabel from __meta_kubernetes_pod_node_name)
@resource.k8s.node.name = scraping AGENT's node (from ${env:K8S_NODE_NAME})
per-node holds  ⇔  for every series, target_node == @resource.k8s.node.name

Dependencies / notes

• Validates the feature PRs (operator per-node + CRD resilience, helm bundling) — most useful
  once those and their custom images are available; tests are skip-guarded so they don't break
  the broader suite where fixtures are absent.
• go vet -tags integration ./test/otel/pernode/... is clean against current main.