Restrict direct apply to verified local k3d targets (#151)

[AntoineToussaint]

Closes #151.

Summary

• Fail closed unless a direct deployment names an exact local k3d context whose complete cluster connection identity matches k3d ownership.
• Make render-only behavior request-scoped and return every rendered service or module tree, its manifests, digest, and verified mutation target as evidence.
• Preserve valid Kustomize image overrides while keeping pull, import, target revalidation, and apply failures fatal.

Test plan

• go test ./...
• go test -race ./pkg/deployments ./pkg/control ./pkg/orchestration ./cmd/deploy ./cmd/ci
• go vet ./...
• go run github.com/golangci/golangci-lint/cmd/golangci-lint@v1.64.8 run --new-from-rev=origin/main ./...

Risk

• Direct apply now intentionally refuses local environments without an explicit cluster.context, or whose canonical kubeconfig connection settings differ from the k3d-owned cluster. Those deployments must declare the exact local target or use the render/GitOps path.