ci: fix Phase 1b post-push CI failures (3 guards)

Phase 1b push (commit 44a85d6) failed three CI guards. None were
caught by `make verify` locally because they're CI-only guards
that aren't part of the Makefile target. This commit fixes all
three.

1. go.mod tidy diff. The go-jose v4 dep was added with `// indirect`
   in go.mod after the initial `go get`, but the codebase imports it
   directly from internal/api/acme/jws.go + service/acme.go +
   handler/acme.go. CI's `go mod tidy && git diff --exit-code go.mod
   go.sum` flagged the staleness. Promoted to a direct require in
   the same `require (...)` block as github.com/aws/aws-sdk-go-v2
   etc.

2. G-3-env-docs-drift.sh. The guard greps `\bCERTCTL_[A-Z_]+\b` in
   docs/ and complains when the bare-prefix forms don't match
   anything defined in config.go. Phase 1a + 1b's docs/acme-server.md
   intro and migration header use bare-prefix forms `CERTCTL_ACME_*`
   and `CERTCTL_ACME_SERVER_*` to describe namespace separation
   (consumer-side ACMEConfig vs server-side ACMEServerConfig). Same
   precedent as the existing CERTCTL_SCEP_ + CERTCTL_TLS_ +
   CERTCTL_QA_* prefix entries already in the guard's ALLOWED list.
   Added CERTCTL_ACME_ + CERTCTL_ACME_SERVER_ to the ALLOWED list
   with a justification comment block matching the existing
   integration-surface allowlist convention.

3. openapi-handler-parity.sh. Distinct from
   internal/api/router/openapi_parity_test.go (which runs at `go
   test` time and has its own SpecParityExceptions map I extended
   in 1a + 1b) — this is a separate CI-only guard that reads
   api/openapi-handler-exceptions.yaml. The 6 Phase-1a routes + 4
   Phase-1b routes (10 ACME endpoints total) were never added to
   that yaml. Same rationale as the SCEP/SCEP-mTLS entries already
   in the file: ACME is a JWS-signed-JSON wire protocol per
   RFC 8555 + RFC 9773, not an OpenAPI-shape REST surface.
   Documenting every endpoint in openapi.yaml would duplicate the
   RFC. The canonical reference is docs/acme-server.md. Phases 2-4
   will add their routes to this yaml in lockstep with router.go.

Verified locally:
  - bash scripts/ci-guards/G-3-env-docs-drift.sh → clean.
  - bash scripts/ci-guards/openapi-handler-parity.sh → clean
    (152 router routes, 136 OpenAPI ops, 18 documented exceptions).
  - All other ci-guards/*.sh → clean.
  - go.mod diff after `go mod tidy` is empty.

api/openapi-handler-exceptions.yaml

@@ -25,3 +25,32 @@ documented_exceptions:
     why: "SCEP-mTLS sibling endpoint, trailing-slash variant."
   - route: "POST /scep-mtls/"
     why: "SCEP-mTLS sibling endpoint, trailing-slash POST variant."
+
+  # ACME server (RFC 8555 + RFC 9773 ARI) — wire-protocol surface.
+  # Like SCEP/EST, ACME is a JWS-signed-JSON wire protocol whose
+  # semantics are dictated by the RFC, not by an OpenAPI schema.
+  # Documenting every endpoint in openapi.yaml would duplicate
+  # RFC 8555 §7.1 + §7.2 + §7.3 with no information gain. The
+  # canonical operator-facing reference is docs/acme-server.md.
+  # Phases 2-4 will extend this list as new-order, finalize, authz,
+  # challenge, cert, key-change, revoke-cert, renewal-info routes land.
+  - route: "GET /acme/profile/{id}/directory"
+    why: "ACME server RFC 8555 §7.1.1 directory; documented in docs/acme-server.md."
+  - route: "HEAD /acme/profile/{id}/new-nonce"
+    why: "ACME server RFC 8555 §7.2 new-nonce; documented in docs/acme-server.md."
+  - route: "GET /acme/profile/{id}/new-nonce"
+    why: "ACME server RFC 8555 §7.2 new-nonce GET form; documented in docs/acme-server.md."
+  - route: "POST /acme/profile/{id}/new-account"
+    why: "ACME server RFC 8555 §7.3 new-account (JWS jwk); documented in docs/acme-server.md."
+  - route: "POST /acme/profile/{id}/account/{acc_id}"
+    why: "ACME server RFC 8555 §7.3.2 + §7.3.6 (JWS kid) account update + deactivation; documented in docs/acme-server.md."
+  - route: "GET /acme/directory"
+    why: "ACME server default-profile shorthand; mirrors per-profile when CERTCTL_ACME_SERVER_DEFAULT_PROFILE_ID is set."
+  - route: "HEAD /acme/new-nonce"
+    why: "ACME server default-profile shorthand for new-nonce HEAD."
+  - route: "GET /acme/new-nonce"
+    why: "ACME server default-profile shorthand for new-nonce GET."
+  - route: "POST /acme/new-account"
+    why: "ACME server default-profile shorthand for new-account."
+  - route: "POST /acme/account/{acc_id}"
+    why: "ACME server default-profile shorthand for account update + deactivation."