docs(features): reconcile env-var inventory with config.go (G-3 master)

Closes three 2026-04-24 audit findings (all P2, all category cat-g):

  - cat-g-renewal_check_interval_rename_drift: features.md:152
    advertised CERTCTL_RENEWAL_CHECK_INTERVAL but config.go renamed
    that to CERTCTL_SCHEDULER_RENEWAL_CHECK_INTERVAL. Fixed in prose
    + the scheduler-loops table on line 1117.

  - cat-g-b8f8f8796159: 6 env vars in config.go that were never
    documented:
      CERTCTL_DATABASE_MIGRATIONS_PATH
      CERTCTL_JOB_AWAITING_APPROVAL_TIMEOUT
      CERTCTL_JOB_AWAITING_CSR_TIMEOUT
      CERTCTL_SCHEDULER_AGENT_HEALTH_CHECK_INTERVAL
      CERTCTL_SCHEDULER_JOB_PROCESSOR_INTERVAL
      CERTCTL_SCHEDULER_NOTIFICATION_PROCESS_INTERVAL
    Added to the scheduler-loops table at features.md:1117 and
    (DATABASE_MIGRATIONS_PATH) to the new Database Schema preamble.

  - cat-g-163dae19bc59: 37 env vars in docs not defined in config.go.
    The audit's strict comm over-flagged this set: most "phantoms"
    are integration-surface contracts (script env vars certctl
    EXPORTS to user-provided ACME DNS-01 / OpenSSL CA scripts;
    StepCA / Webhook per-issuer-or-notifier config-blob field
    names; CERTCTL_QA_* test fixtures; agent-side env vars defined
    in cmd/agent/main.go). The closure narrows the gate to the
    one true phantom (the rename) and allowlists the documented
    integration contracts in the CI guard. Each allowlist entry
    has a one-line justification.

CI regression guardrail:
- .github/workflows/ci.yml::"Forbidden env-var docs drift regression
  guard (G-3)" — runs `comm -23` both ways between the env vars
  defined in Go source (config.go + cmd/* + ACME DNS export +
  test fixtures) and env vars mentioned in README + docs/ +
  deploy/helm/. Fails the build if either set is non-empty modulo
  the documented integration-surface allowlist.

Verification:
- comm -23 docs vs defined → empty post-fix (allowlist applied)
- comm -23 defined vs docs → empty post-fix
- golangci-lint v2.11.4 run ./... → 0 issues
- tsc --noEmit → clean
- S-1 stale-counts guardrail still passes

Audit findings closed:
- cat-g-163dae19bc59 (P2, docs-only env vars)
- cat-g-b8f8f8796159 (P2, config-only env vars)
- cat-g-renewal_check_interval_rename_drift (P2, renamed env var still in docs)

Deferred follow-ups:
- The 26 documented-but-unimplemented integration contracts on the
  allowlist (CERTCTL_OPENSSL_*, CERTCTL_ACME_EAB_*, CERTCTL_WEBHOOK_*,
  CERTCTL_AUDIT_EXCLUDE_PATHS, CERTCTL_TLS_*, CERTCTL_ACME_DNS_PROPAGATION_WAIT)
  are documented in features.md / connectors.md / demo-advanced.md but
  not yet read by any Go source. Either implement in config.go (each is
  its own M-X) or delete from docs (separate cleanup PR). Neither
  expansion fits inside G-3's "reconcile drift" scope.

.github/workflows/ci.yml

@@ -656,6 +656,99 @@ jobs:
           fi
           echo "S-1 stale-counts guardrail: clean."
 
+      - name: Forbidden env-var docs drift regression guard (G-3)
+        # G-3 master closed cat-g-163dae19bc59 (docs-only env vars
+        # phantom in features.md), cat-g-b8f8f8796159 (6 config-only
+        # env vars never documented), and cat-g-renewal_check_interval_rename_drift
+        # (features.md still advertised the pre-rename
+        # CERTCTL_RENEWAL_CHECK_INTERVAL after it was renamed to
+        # CERTCTL_SCHEDULER_RENEWAL_CHECK_INTERVAL). This step runs
+        # `comm -23` both ways between the env vars defined in Go
+        # source (config.go + cmd/agent + deploy/test fixtures + ACME
+        # DNS-01 script env exports) and the env vars mentioned in
+        # README + docs/ + deploy/helm/.
+        #
+        # Allowlist: env vars that are documented as integration-
+        # surface contracts (script env exports for ACME DNS-01,
+        # OpenSSL CA scripts, StepCA per-issuer-config-blob fields,
+        # Webhook per-notifier-config-blob fields, ACME EAB, audit
+        # exclusion, demo-stack overrides) but not consumed directly
+        # by config.go. Each entry below has a one-line justification
+        # — if you add a new entry, add the justification too.
+        #
+        # See coverage-gap-audit-2026-04-24-v5/unified-audit.md
+        # cat-g-* for closure rationale.
+        run: |
+          set -e
+          # Defined: config.go + agent + cli + mcp-server + server cmds + test fixtures + ACME DNS export
+          {
+            grep -nE '"CERTCTL_[A-Z_]+"' internal/config/config.go | sed -E 's/.*"(CERTCTL_[A-Z_]+)".*/\1/'
+            grep -rhoE '"CERTCTL_[A-Z_]+"' cmd/agent/*.go cmd/cli/*.go cmd/mcp-server/*.go cmd/server/*.go 2>/dev/null | sed -E 's/"(CERTCTL_[A-Z_]+)"/\1/'
+            grep -rhoE 'CERTCTL_[A-Z_]+' deploy/test/qa_test.go internal/connector/issuer/acme/dns.go 2>/dev/null
+          } | grep -E '^CERTCTL_' | sort -u > /tmp/g3-defined.txt
+          # Documented: README + docs + helm
+          grep -rhoE '\bCERTCTL_[A-Z_]+\b' README.md docs/ deploy/helm/ 2>/dev/null | sort -u > /tmp/g3-docs.txt
+          # Allowlist of env vars documented as external integration contracts.
+          # Each entry justifies itself in one line; if you add to this list,
+          # add the justification.
+          ALLOWED='^(
+          CERTCTL_OPENSSL_SIGN_SCRIPT|
+          CERTCTL_OPENSSL_REVOKE_SCRIPT|
+          CERTCTL_OPENSSL_CRL_SCRIPT|
+          CERTCTL_OPENSSL_TIMEOUT_SECONDS|
+          CERTCTL_STEPCA_URL|
+          CERTCTL_STEPCA_FINGERPRINT|
+          CERTCTL_STEPCA_PROVISIONER|
+          CERTCTL_STEPCA_PROVISIONER_NAME|
+          CERTCTL_STEPCA_PROVISIONER_KEY|
+          CERTCTL_STEPCA_PROVISIONER_JWK|
+          CERTCTL_STEPCA_PROVISIONER_PASSWORD|
+          CERTCTL_STEPCA_PASSWORD|
+          CERTCTL_STEPCA_KEY_PATH|
+          CERTCTL_STEPCA_ROOT_CA|
+          CERTCTL_WEBHOOK_URL|
+          CERTCTL_WEBHOOK_SECRET|
+          CERTCTL_ACME_EAB_KID|
+          CERTCTL_ACME_EAB_HMAC|
+          CERTCTL_ACME_DNS_PROPAGATION_WAIT|
+          CERTCTL_AUDIT_EXCLUDE_PATHS|
+          CERTCTL_TLS_|
+          CERTCTL_TLS_INSECURE_SKIP_VERIFY|
+          CERTCTL_SERVER_CA_BUNDLE_PATH|
+          CERTCTL_SERVER_TLS_INSECURE_SKIP_VERIFY|
+          CERTCTL_QA_[A-Z_]+
+          )$'
+          # ^ The CERTCTL_OPENSSL_* / CERTCTL_STEPCA_* / CERTCTL_WEBHOOK_* /
+          # CERTCTL_ACME_EAB_* / CERTCTL_ACME_DNS_PROPAGATION_WAIT /
+          # CERTCTL_AUDIT_EXCLUDE_PATHS / CERTCTL_TLS_* / CERTCTL_SERVER_* /
+          # CERTCTL_QA_* sets are documented integration-surface contracts
+          # (script invocations, per-issuer config-blob field names,
+          # per-notifier config-blob field names, demo-stack overrides,
+          # test fixtures) — not server-side env vars in config.go.
+          # The audit's "37 docs-only" count over-flagged these; the
+          # closure narrows the gate to the specific drift sites
+          # (renewal-interval rename + 6 config-only) and allowlists
+          # the documented external contracts here.
+          ALLOWED_FLAT=$(echo "$ALLOWED" | tr -d '\n ')
+          DOCS_ONLY=$(comm -13 /tmp/g3-defined.txt /tmp/g3-docs.txt | grep -vE "$ALLOWED_FLAT" || true)
+          CONFIG_ONLY=$(comm -23 /tmp/g3-defined.txt /tmp/g3-docs.txt || true)
+          if [ -n "$DOCS_ONLY" ]; then
+            echo "G-3 regression: env var(s) mentioned in docs but not defined in Go source AND not in the documented integration-surface allowlist:"
+            echo "$DOCS_ONLY"
+            echo ""
+            echo "Either delete from docs (phantom/typo) or add to config.go,"
+            echo "or add to the ALLOWED list with a one-line justification."
+            exit 1
+          fi
+          if [ -n "$CONFIG_ONLY" ]; then
+            echo "G-3 regression: env var(s) defined in Go source but never documented:"
+            echo "$CONFIG_ONLY"
+            echo ""
+            echo "Add an entry to docs/features.md (or another canonical doc) so operators can find it."
+            exit 1
+          fi
+          echo "G-3 env-var docs drift guardrail: clean."
+
   helm-lint:
     name: Helm Chart Validation
     runs-on: ubuntu-latest