fix(automerge): narrow infra/ regex; let cron-only changes auto-merge

.github/workflows/claude-author-automerge.yml

@@ -14,8 +14,16 @@ name: Claude-author Auto-merge (reusable)
 #     - DB migrations / SQL files
 #     - billing / payment / pricing / invoice
 #     - production infra: Dockerfile, docker-compose, .github/workflows,
-#       .github/risk-paths.yml, .github/CODEOWNERS, infra/, terraform/,
-#       pulumi/, k8s/, fly.toml, deploy/, deploy*.{sh,yaml}
+#       .github/risk-paths.yml, .github/CODEOWNERS, infra/iam/, infra
+#       subdirs (deploy/terraform/pulumi/k8s/cloudformation/ansible/
+#       digitalocean/scanner-id/nginx), systemd units + Terraform files
+#       anywhere under infra/, top-level terraform/, pulumi/, k8s/,
+#       fly.toml, deploy/, deploy*.{sh,yaml}.
+#       Specifically NOT risky under infra/: cron schedule files
+#       (infra/crontabs/*.crontab), runbook .md files, example configs.
+#       The earlier broad `^infra/.*` rule over-classified cron-only
+#       changes (lesson 2026-05-04, wxa_vpn#250) and was narrowed
+#       2026-05-20.
 #
 # Customer-copy diffs (legal / marketing wording) are NOT mechanically
 # detected — Claude Review handles that semantically and blocks via the
@@ -218,7 +226,10 @@ jobs:
           ^\.github/workflows/.*
           ^\.github/risk-paths\.yml$
           ^\.github/CODEOWNERS$
-          ^infra/.*
+          ^infra/iam/.*
+          ^infra/(deploy|terraform|pulumi|k8s|cloudformation|ansible|digitalocean|scanner-id)/.*
+          ^infra/nginx.*
+          ^infra/.*\.(service|slice|timer|tf|hcl|sh)$
           ^terraform/.*
           ^pulumi/.*
           ^k8s/.*

selftest/test_automerge_risk_patterns.sh

@@ -0,0 +1,133 @@
+#!/usr/bin/env bash
+# Tests for the risk-tier path regex in claude-author-automerge.yml.
+#
+# The regex list was over-classifying cron-only changes (lesson 2026-05-04
+# after wxa_vpn#250; concrete case: wxa_vpn#439 + #441 in 2026-05-20). This
+# script bakes the expected matching behavior into version control so future
+# narrowings or expansions to the regex list cannot silently regress.
+#
+# Run from the repo root:
+#   bash selftest/test_automerge_risk_patterns.sh
+set -euo pipefail
+
+# Mirror the patterns block from .github/workflows/claude-author-automerge.yml.
+# Keep these in lock-step — if you edit one, edit the other.
+patterns='^(.*/)?(auth|login|session|oauth|sso)(/|$)
+^(.*/)?secrets(/|$)
+^(.*/)?\.env($|\..*)
+^(.*/)?keychain.*
+^(.*/)?credentials.*
+^(.*/)?migrations(/|$)
+.*\.sql$
+^(.*/)?(billing|payment[s]?|pricing|invoice[s]?)(/|$)
+(^|/)Dockerfile(\..*)?$
+^docker-compose.*\.ya?ml$
+^\.github/workflows/.*
+^\.github/risk-paths\.yml$
+^\.github/CODEOWNERS$
+^infra/iam/.*
+^infra/(deploy|terraform|pulumi|k8s|cloudformation|ansible|digitalocean|scanner-id)/.*
+^infra/nginx.*
+^infra/.*\.(service|slice|timer|tf|hcl|sh)$
+^terraform/.*
+^pulumi/.*
+^k8s/.*
+^fly\.toml$
+^deploy/.*
+(^|/)deploy.*\.(sh|ya?ml)$'
+
+matches() {
+  local f=$1
+  local pat
+  while IFS= read -r pat; do
+    pat="${pat#"${pat%%[![:space:]]*}"}"
+    [ -z "$pat" ] && continue
+    if echo "$f" | grep -Eq "$pat"; then
+      return 0
+    fi
+  done <<< "$patterns"
+  return 1
+}
+
+# Cases the regex MUST flag as risky (manual click-merge).
+RISKY=(
+  "src/auth/login.py"
+  "secrets/api-keys.json"
+  ".env.production"
+  "src/keychain_helpers.py"
+  "credentials.py"
+  "migrations/031_cdn_operator.sql"
+  "src/db/schema.sql"
+  "billing/invoices.py"
+  "Dockerfile"
+  "docker-compose.yml"
+  ".github/workflows/deploy.yml"
+  ".github/risk-paths.yml"
+  ".github/CODEOWNERS"
+  "infra/iam/scanner-role.json"          # IAM policy
+  "infra/iam/wxa-vpn-api-policy.json"
+  "infra/terraform/main.tf"              # IaC under infra/
+  "infra/digitalocean/systemd/wxa.service"
+  "infra/scanner-id/identity.json"
+  "infra/nginx/honeypot.conf"
+  "infra/nginx-checkip-vhost.conf"       # top-level nginx config
+  "infra/wxa-vpn-api.service"            # systemd unit
+  "infra/wxa-workload.slice"
+  "infra/wxa-gt-builder.timer"
+  "infra/some.tf"
+  "infra/deploy-netflow-cron.sh"         # shell script
+  "infra/setup-actions-runner.sh"
+  "infra/deploy-systemd.sh"
+  "terraform/main.tf"
+  "pulumi/index.ts"
+  "k8s/deployment.yaml"
+  "fly.toml"
+  "deploy/prod.sh"
+  "deploy.sh"
+  "deploy-staging.yml"
+)
+
+# Cases the regex MUST allow through to auto-merge (the historical false positives).
+SAFE=(
+  "src/wxa_vpn/api/routes.py"
+  "tests/test_anything.py"
+  "docs/data-dictionary.md"
+  "scripts/run_analysis.py"
+  "infra/crontabs/wxa-scanner.crontab"   # cron schedule — wxa_vpn#439 case
+  "infra/crontabs/wxa-scanner-active.crontab"
+  "infra/crontabs/README.md"
+  "infra/crontabs/wxa-scanner-slow.crontab"
+  "infra/aws-scanner-setup.md"           # runbook docs
+  "infra/crontab.example"                # example config
+  "infra/README.md"
+)
+
+failed=0
+
+echo "Risky paths (must match):"
+for p in "${RISKY[@]}"; do
+  if matches "$p"; then
+    echo "  ✓ $p"
+  else
+    echo "  ✗ $p (FAILED — should have matched)"
+    failed=$((failed + 1))
+  fi
+done
+
+echo ""
+echo "Safe paths (must NOT match):"
+for p in "${SAFE[@]}"; do
+  if matches "$p"; then
+    echo "  ✗ $p (FAILED — should NOT have matched)"
+    failed=$((failed + 1))
+  else
+    echo "  ✓ $p"
+  fi
+done
+
+echo ""
+if [ "$failed" -gt 0 ]; then
+  echo "FAIL: $failed case(s) regressed."
+  exit 1
+fi
+echo "OK: all risk-pattern cases pass."