test: harden harness reproducibility and cleanup

scripts/test-env

@@ -4,11 +4,51 @@ set -eu
 repo_root=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
 command=${1:-}
 if [ -z "$command" ]; then
-  echo "usage: scripts/test-env doctor|coverage|status|logs|collect|recover|reuse|stop|reset|purge [--run-id ID]" >&2
+  echo "usage: scripts/test-env doctor [--e2e] | coverage|status|logs|collect|recover|reuse|stop|reset|purge|gc [options]" >&2
   exit 2
 fi
 shift
 
+if [ "$command" = --help ] || [ "$command" = -h ]; then
+  echo "usage: scripts/test-env doctor [--e2e] | coverage|status|logs|collect|recover|reuse|stop|reset|purge|gc [options]"
+  exit 0
+fi
+
+fail() { printf '%s\n' "test-env: $*" >&2; exit 2; }
+
+doctor() {
+  e2e=no
+  while [ "$#" -gt 0 ]; do
+    case $1 in
+      --e2e) e2e=yes ;;
+      --help|-h) echo "usage: scripts/test-env doctor [--e2e]"; return 0 ;;
+      *) fail "unknown doctor option $1" ;;
+    esac
+    shift
+  done
+  docker version >/dev/null || fail "Docker is unavailable"
+  docker compose version >/dev/null || fail "Docker Compose is unavailable"
+  defaults=$repo_root/test/harness/defaults.toml
+  [ -r "$defaults" ] || fail "harness defaults are unreadable"
+  floor=$(awk -F '=' '/^free_space_floor_bytes[[:space:]]*=/{gsub(/[[:space:]]/, "", $2); print $2; exit}' "$defaults")
+  case $floor in ''|*[!0-9]*) fail "harness free-space floor is invalid" ;; esac
+  available_kib=$(df -Pk "$repo_root" | awk 'NR == 2 { print $4 }')
+  case $available_kib in ''|*[!0-9]*) fail "could not determine available disk space" ;; esac
+  available_bytes=$((available_kib * 1024))
+  [ "$available_bytes" -ge "$floor" ] || fail "available disk space $available_bytes is below harness floor $floor"
+  printf 'docker=ready compose=ready disk_available_bytes=%s disk_floor_bytes=%s cpus=%s\n' "$available_bytes" "$floor" "$(getconf _NPROCESSORS_ONLN 2>/dev/null || printf '?')"
+  if [ "$e2e" = yes ]; then
+    "$repo_root/scripts/windows/test-host" status
+  fi
+  cd "$repo_root"
+  exec docker compose -f deploy/compose.yaml run --rm toolchain go run ./test/harness doctor
+}
+
+if [ "$command" = doctor ]; then
+  doctor "$@"
+  exit $?
+fi
+
 docker version >/dev/null
 docker compose version >/dev/null