fix: feat: supervisor auto-retriggers CI after infra-only exhaustion (#185)

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

lib/ci-helpers.sh

@@ -15,3 +15,45 @@ ci_passed() {
   fi
   return 1
 }
+
+# classify_pipeline_failure <repo_id> <pipeline_num>
+# Classifies a pipeline's failure type by inspecting all failed steps.
+# Outputs "infra" if every failed step is a git step with exit code 128 or 137.
+# Outputs "code" otherwise (including when steps cannot be determined).
+# Returns 0 for infra, 1 for code or unclassifiable.
+classify_pipeline_failure() {
+  local repo_id="$1" pip_num="$2"
+  local pip_json failed_steps all_infra _sname _ecode
+
+  pip_json=$(woodpecker_api "/repos/${repo_id}/pipelines/${pip_num}" 2>/dev/null) || {
+    echo "code"; return 1
+  }
+
+  failed_steps=$(printf '%s' "$pip_json" | jq -r '
+    .workflows[]?.children[]? |
+    select(.state == "failure" or .state == "error" or .state == "killed") |
+    "\(.name)\t\(.exit_code)"' 2>/dev/null)
+
+  if [ -z "$failed_steps" ]; then
+    echo "code"; return 1
+  fi
+
+  all_infra=true
+  while IFS=$'\t' read -r _sname _ecode; do
+    [ -z "$_sname" ] && continue
+    # git step with exit 128 (connection/rate-limit) or 137 (OOM) → infra
+    if [[ "$_sname" == git* ]] && { [ "$_ecode" = "128" ] || [ "$_ecode" = "137" ]; }; then
+      : # infra step — continue checking remaining steps
+    else
+      all_infra=false
+      break
+    fi
+  done <<< "$failed_steps"
+
+  if [ "$all_infra" = true ]; then
+    echo "infra"
+    return 0
+  fi
+  echo "code"
+  return 1
+}