feat(tunnel): zero-touch tunnel enrollment — control-plane PKI, host agent, iOS, nginx isolation

Customers install one command / log in once; hardware-generated keys never leave the
device; CSRs return certs + subdomain; frpc + base-app run as durable services. No .p12,
no manual cert import. Implements the MVP fast-path of docs/PLAN_TUNNEL_AUTOMATION.md.

Control-plane / PKI (control-plane/):
- ca/x509-assembler.ts: single KMS-signed real X.509 issuance primitive (Ed25519 + P-256)
- ca/csr-ec.ts: P-256 PKCS#10 proof-of-possession (verifyCsrPoPEc) + CSR-key routing
- ca/frpclient-issue.ts, ca/device-issue.ts: P-256 frp-client + device leaf signers
- ca/rotate.ts + api/renew.ts: real-X.509 /renew + /device/:id/renew (mTLS current cert)
- registry/devices.ts: device registry + per-account cap/rate-limit
- auth/session.ts: device:enroll capability token mint/verify
- api/device-enroll.ts: POST /device/enroll (ownership-gated, deny-by-default)
- pairing/native-redeem.ts + shared gateAndConsumePairingCode; api/provision.ts native arm
- boot/native-ca.ts + main.ts: wire two P-256 CAs + issuers + routers (dev / KMS fail-fast)

Contracts: relay-contracts enroll right; relay-auth SPIFFE /device/ arm + spiffeIdFor(kind)

Host agent (agent/):
- transport/frpcToml.ts; provision/frpcBinary.ts + untar.ts (verify-download + traversal-safe extract)
- keys P-256 keygen/CSR/loadIdentity; service two-unit install + BIND_HOST loopback S-GATE
- net/loopbackLiteral.ts strict guard; health/probe.ts + transport/frpSupervise.ts; cli pair --install

iOS (ios/Packages/ClientTLS): SecureEnclaveKey + CertificateSigningRequest + DeviceEnrollmentClient
+ Keychain enroll refactor (SecKey/Security.framework end-to-end, avoids the -25300 trap)

Isolation (deploy/nginx): njs/getCertSub.js SAN parser + zone-anchored map -> 403

Verified: 758 tests green (control-plane 246, agent 267, relay-auth 133, relay-contracts 85,
iOS ClientTLS 27), all tsc clean; real nginx+njs docker 403/200/400; Swift CSR accepted by
the real control-plane verifier; frpc extract byte-identical to `tar -xO`. Cross-validation
caught + fixed 5 real defects (1 critical, 4 high). Remaining = infra (KMS, nginx deploy,
VPS frps, physical iPhone) per PROGRESS_LOG runbook.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

agent/src/config/agentConfig.ts

@@ -9,6 +9,7 @@
 import { homedir } from 'node:os'
 import { join } from 'node:path'
 import { z } from 'zod'
+import { isLoopbackHostLiteral } from '../net/loopbackLiteral.js'
 
 export interface AgentConfig {
   readonly relayUrl: string
@@ -19,9 +20,12 @@ export interface AgentConfig {
   readonly hostId: string | null
 }
 
-const LOOPBACK_HOSTNAMES: readonly string[] = ['localhost', '127.0.0.1', '::1', '[::1]']
-
-/** True iff `url` is ws:// to a loopback host (127.0.0.0/8, localhost, or ::1). */
+/**
+ * True iff `url` is ws:// to a loopback host (a well-formed 127.0.0.0/8 IPv4 literal, localhost, or
+ * ::1). Uses the shared strict check so a crafted suffixed hostname such as
+ * `ws://127.0.0.1.attacker.example.com:3000` — which the outbound dial would DNS-resolve and connect
+ * to wherever it points — is REJECTED, closing the anti-SSRF bypass (not merely `startsWith('127.')`).
+ */
 export function isLoopbackWsUrl(url: string): boolean {
   let parsed: URL
   try {
@@ -30,8 +34,7 @@ export function isLoopbackWsUrl(url: string): boolean {
     return false
   }
   if (parsed.protocol !== 'ws:') return false
-  const host = parsed.hostname
-  return LOOPBACK_HOSTNAMES.includes(host) || host.startsWith('127.')
+  return isLoopbackHostLiteral(parsed.hostname)
 }
 
 function hasScheme(url: string, scheme: string): boolean {