infra(argo): plain smoke-test template + scripts/argo-smoke.sh

Adds a no-wrapper L40S smoke runner alongside the nsys/sanitizer
templates. Same compile + checkout + data-mount layout, no profiler
binary, no sanitizer instrumentation, no MinIO artefact upload — just
a plain test execution against the full training-data PVC.

Use case: validate a smoke test passes on the real 27-month dataset
when local data is too short (laptop only has 1 quarter of MBP-10/
trades, fxcache truncates below the 10-month minimum).

- infra/k8s/argo/smoke-test-template.yaml: WorkflowTemplate
  smoke-test, entrypoint smoke-run, default test
  multi_fold_convergence::test_multi_fold_convergence.
- infra/k8s/argo/kustomization.yaml: register the new template.
- infra/k8s/argo/argo-workflow-netpol.yaml: extend the
  sanitizer/nsys NetworkPolicy podSelector to include smoke-test
  (identical egress requirements: git fetch, ci-builder pull,
  training-data PVC).
- scripts/argo-smoke.sh: thin wrapper mirroring argo-nsys.sh /
  argo-sanitizer.sh (--multi-fold default, --test, --ref, --watch).

Verified: kustomize dry-run clean, kubectl apply -k creates the
template + reconfigures the netpol live in foxhunt namespace.

scripts/argo-smoke.sh

@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+# Run a smoke test on L40S via Argo Workflows — no profiler, no sanitizer.
+#
+# Use this when you want to validate that a smoke test passes against the
+# full training-data PVC (27 months of OHLCV + MBP-10 + trades) without
+# nsys profile overhead or sanitizer instrumentation. Iteration cycle is
+# faster than argo-nsys.sh / argo-sanitizer.sh because there's no artefact
+# upload step.
+#
+# Why L40S not local: the laptop has only 1 quarter of MBP-10/trades data,
+# which truncates the fxcache below the 10-month minimum that the
+# multi_fold_convergence smoke needs.
+#
+# Usage:
+#   ./scripts/argo-smoke.sh                                   # multi_fold_convergence (default)
+#   ./scripts/argo-smoke.sh --test magnitude_distribution     # different test
+#   ./scripts/argo-smoke.sh --ref <sha>                       # specific commit
+#   ./scripts/argo-smoke.sh --watch                           # follow logs
+#
+# Requires: argo CLI
+
+set -euo pipefail
+
+TEST_NAME="multi_fold_convergence::test_multi_fold_convergence"
+COMMIT_REF="HEAD"
+GPU_POOL=""
+WATCH=false
+
+usage() {
+  cat <<EOF
+Usage: $(basename "$0") [OPTIONS]
+
+Plain smoke-test runner on L40S (no profiler, no sanitizer).
+
+Options:
+  --test <name>        Smoke test name (default: $TEST_NAME)
+                       Common values:
+                         multi_fold_convergence::test_multi_fold_convergence
+                         magnitude_distribution::test_magnitude_distribution
+                         performance::test_real_data_single_epoch
+                         iqn_quantile_monotonicity::iqn_multi_quantile_heads_produce_monotonic_estimates
+  --multi-fold         Shortcut: --test multi_fold_convergence::test_multi_fold_convergence
+                       (default — exercises fold-boundary code paths)
+  --ref <ref>          Git ref to test (default: HEAD)
+  --gpu-pool <pool>    GPU node pool (default: ci-training-l40s)
+  --watch              Follow workflow logs
+  -h, --help           Show this help
+EOF
+  exit 0
+}
+
+while [[ $# -gt 0 ]]; do
+  case $1 in
+    --test)        TEST_NAME="$2"; shift 2 ;;
+    --multi-fold)  TEST_NAME="multi_fold_convergence::test_multi_fold_convergence"; shift ;;
+    --ref)         COMMIT_REF="$2"; shift 2 ;;
+    --gpu-pool)    GPU_POOL="$2"; shift 2 ;;
+    --watch)       WATCH=true; shift ;;
+    -h|--help)     usage ;;
+    *)             echo "Unknown option: $1"; usage ;;
+  esac
+done
+
+if [ "$COMMIT_REF" = "HEAD" ]; then
+  COMMIT_REF=$(git rev-parse HEAD)
+fi
+
+CMD="argo submit -n foxhunt --from=wftmpl/smoke-test"
+CMD="$CMD -p commit-ref=$COMMIT_REF"
+CMD="$CMD -p test-name=$TEST_NAME"
+[[ -n "$GPU_POOL" ]] && CMD="$CMD -p gpu-pool=$GPU_POOL"
+
+if $WATCH; then
+  CMD="$CMD --watch"
+fi
+
+echo "Submitting smoke workflow..."
+echo "  commit: $(echo "$COMMIT_REF" | cut -c1-8)"
+echo "  test:   $TEST_NAME"
+echo ""
+eval "$CMD"