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>

relay-auth/src/types.ts

@@ -97,7 +97,7 @@ export interface AuditEvent {
   readonly remoteAddrHash: string
 }
 
-export type SpiffeId = string // 'spiffe://relay.<domain>/account/<accountId>/host/<hostId>'
+export type SpiffeId = string // 'spiffe://relay.<domain>/account/<accountId>/(host|device)/<id>'
 
 export interface RateLimitPolicy {
   readonly connectPerMin: number
@@ -227,11 +227,13 @@ export const RateLimitPolicySchema = z
   .strict()
 
 /**
- * SPIFFE-ID validator: accepts the `spiffe://relay.<domain>/account/<a>/host/<h>` form and
- * REJECTS path-traversal (`..`) or wildcard (`*`). Segment chars are restricted (no `/`).
+ * SPIFFE-ID validator: accepts BOTH the host arm `spiffe://relay.<domain>/account/<a>/host/<h>`
+ * and the device arm `.../account/<a>/device/<d>` (FIX H-cp-2 / H-native-6, added in lockstep
+ * with the control-plane device issuer). REJECTS path-traversal (`..`) or wildcard (`*`); the
+ * kind segment is exactly `host` or `device`. Segment chars are restricted (no `/`).
  */
 const SPIFFE_ID_RE =
-  /^spiffe:\/\/relay\.[a-z0-9.-]+\/account\/[A-Za-z0-9_-]+\/host\/[A-Za-z0-9_-]+$/
+  /^spiffe:\/\/relay\.[a-z0-9.-]+\/account\/[A-Za-z0-9_-]+\/(?:host|device)\/[A-Za-z0-9_-]+$/
 export const SpiffeIdSchema = z
   .string()
   .regex(SPIFFE_ID_RE, 'invalid SPIFFE-ID form')