fix(k8s): align local helpers with AgentTeams contracts

[RerankerGuo]

Summary

• make the local kind helpers consume the canonical AGENTTEAMS_* environment contract and defaults
• delegate local image builds to the maintained Makefile targets, then select the matching OpenClaw or CoPaw Manager image
• read the renamed runtime Secret keys and keep the teardown helper on the same cluster/namespace contract

Verification

• bash -n hack/local-k8s-up.sh hack/local-k8s-down.sh
• git diff --check
• stubbed full up/down runs for CoPaw skip-build and OpenClaw build/load paths
• Makefile dry-run confirms canonical image tags and AGENTTEAMS_CONTROLLER_IMAGE build args
• Helm v3.14 lint and template with the generated CoPaw/local-image overrides