ci: redirect Phoenix TMPDIR in test.sh to avoid MPI session dir failures

Phoenix compute nodes have a small /tmp. With 8 parallel test
threads each spawning MPI processes over ~96 minutes, it fills up
and ORTE fails to create its session directory, causing the last
batch of tests to fail with 'No such file or directory'. Apply the
same TMPDIR redirect to project storage that bench.sh already uses.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sbryngelson

.github/workflows/common/test.sh

@@ -8,6 +8,19 @@ set -euo pipefail
 source .github/scripts/gpu-opts.sh
 build_opts="$gpu_opts"
 
+# --- Phoenix TMPDIR setup ---
+# Phoenix compute nodes have a small /tmp. With 8 parallel test threads each
+# spawning MPI processes, it fills up and ORTE session dir creation fails.
+# Redirect TMPDIR to project storage, same as bench.sh.
+if [ "$job_cluster" = "phoenix" ]; then
+    tmpbuild=/storage/project/r-sbryngelson3-0/sbryngelson3/mytmp_build
+    currentdir=$tmpbuild/run-$(( RANDOM % 9000 ))
+    mkdir -p $tmpbuild
+    mkdir -p $currentdir
+    export TMPDIR=$currentdir
+    trap 'rm -rf "$currentdir" || true' EXIT
+fi
+
 # --- Build (if not pre-built on login node) ---
 # Phoenix builds inside SLURM; Frontier pre-builds via build.sh on the login node.
 # Phoenix builds inside SLURM on heterogeneous compute nodes — always start fresh