fix(controlplane): clean up org config after deprovision

[EDsCODE]

Summary

• finalize managed warehouse deprovision by removing the org config rows after Duckling and Lakekeeper teardown succeeds
• keep cleanup retryable by guarding the final transaction on deleting state
• update the deprovision runbook to verify automatic org cleanup with a manual fallback

Test plan

• go test -tags kubernetes ./controlplane/provisioner -run 'TestReconcileDeleting(DeletesCR|RetriesOnNonNotFoundError|_TearsDownLakekeeper)'
• go test ./tests/configstore -run 'TestFinalizeWarehouseDeletion'
• just test-controlplane-k8s
• just test-configstore-integration

Notes

• just lint was attempted locally, but golangci-lint is not installed in this checkout environment and there is no local flox environment.