feat(relay): rendezvous-relay service — 7 packages + plans (contracts/transport/agent/control-plane/e2e/auth/web)

Multi-tenant reverse-tunnel service ("ngrok for Claude Code" with E2E): a
host-agent dials OUT to an operator-run relay; external devices reach the host
THROUGH the relay, routed by per-tenant subdomain, forwarding ciphertext only
(the relay never sees plaintext). Lets a customer reach their own self-hosted
web-terminal from anywhere with zero networking setup.

Packages — all tsc-strict + vitest green (656 tests), cross-package integration verified:
- relay-contracts: frozen shared contracts (mux frame codec, data model,
  capability token, E2E envelope, pairing) — the src/types.ts analog
- term-relay:   native WS mux + stateless data plane (subdomain routing, ciphertext forward)
- agent:        host-agent (pairing, per-host Ed25519 + mTLS dial-out, forwards to 127.0.0.1:3000)
- control-plane: accounts/hosts registry, pairing-code flow, routing table, provisioning
- relay-e2e:    browser<->agent E2E (X25519 ECDH through relay, AEAD, anti-replay, recoverable replay key)
- relay-auth:   Passkey/WebAuthn, capability tokens, per-host certs, deny-by-default tenant isolation
- relay-web:    browser login + Web Crypto E2E + client-side preview rendering

Security invariants INV1-15 enforced; cross-tenant isolation CI tripwire live
(.github/workflows/relay-tripwire.yml). Design + implementation-level plans in
docs/PLAN_RELAY_*.md and docs/EXPLORE_RELAY_SERVICE.md.

NOTE: generated autonomously per the reviewed plans. The security-critical
packages (relay-e2e, relay-auth) REQUIRE expert security audit before any real
deployment — passing tests prove self-consistency, not resistance to attackers.
Base app (src/, public/) unchanged; concurrent desktop work left uncommitted.

relay-contracts/test/capability-pairing.test.ts

@@ -0,0 +1,95 @@
+import { describe, expect, it } from 'vitest'
+import {
+  CapabilityTokenSchema,
+  EnrollResultSchema,
+  NotImplementedInContractsError,
+  PairingCodeRecordSchema,
+  verifyCapabilityToken,
+} from '../src/index.js'
+
+const UUID = '22222222-2222-4222-8222-222222222222'
+const TS = '2026-07-01T00:00:00.000Z'
+
+describe('§4.3 CapabilityToken shape validation', () => {
+  const valid = {
+    sub: 'device:1',
+    aud: 'alice',
+    host: UUID,
+    rights: ['attach'],
+    iat: 1000,
+    exp: 2000,
+    jti: 'jti-1',
+  }
+
+  it('accepts a well-formed token body', () => {
+    expect(CapabilityTokenSchema.parse(valid).rights).toEqual(['attach'])
+  })
+
+  it('rejects empty rights', () => {
+    expect(CapabilityTokenSchema.safeParse({ ...valid, rights: [] }).success).toBe(false)
+  })
+
+  it('rejects duplicate rights', () => {
+    expect(
+      CapabilityTokenSchema.safeParse({ ...valid, rights: ['attach', 'attach'] }).success,
+    ).toBe(false)
+  })
+
+  it('rejects exp <= iat', () => {
+    expect(CapabilityTokenSchema.safeParse({ ...valid, exp: 1000 }).success).toBe(false)
+  })
+
+  it('rejects an unknown right', () => {
+    expect(CapabilityTokenSchema.safeParse({ ...valid, rights: ['destroy'] }).success).toBe(false)
+  })
+
+  it('verifyCapabilityToken is a frozen stub (crypto verify owned by P5)', () => {
+    expect(() => verifyCapabilityToken('raw', 'alice', Date.now())).toThrow(
+      NotImplementedInContractsError,
+    )
+  })
+})
+
+describe('§4.5 pairing / enroll shapes', () => {
+  it('accepts a valid EnrollResult', () => {
+    const rec = {
+      hostId: UUID,
+      subdomain: 'alice',
+      cert: '-----BEGIN CERTIFICATE-----',
+      caChain: '-----BEGIN CERTIFICATE-----',
+      hostContentSecret: new Uint8Array([9, 8, 7]),
+    }
+    expect(EnrollResultSchema.parse(rec).hostContentSecret).toBeInstanceOf(Uint8Array)
+  })
+
+  it('rejects an EnrollResult with a non-bytes hostContentSecret', () => {
+    expect(
+      EnrollResultSchema.safeParse({
+        hostId: UUID,
+        subdomain: 'a',
+        cert: 'c',
+        caChain: 'c',
+        hostContentSecret: 'not-bytes',
+      }).success,
+    ).toBe(false)
+  })
+
+  it('accepts a PairingCodeRecord (redeemed and unredeemed)', () => {
+    expect(
+      PairingCodeRecordSchema.parse({
+        codeHash: 'h',
+        accountId: UUID,
+        expiresAt: TS,
+        redeemedAt: null,
+      }).redeemedAt,
+    ).toBeNull()
+    expect(
+      PairingCodeRecordSchema.parse({
+        codeHash: 'h',
+        accountId: UUID,
+        expiresAt: TS,
+        redeemedAt: TS,
+      }).redeemedAt,
+    ).toBe(TS)
+  })
+})