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-web/test/ws-transport.test.ts

@@ -0,0 +1,128 @@
+import { describe, expect, it } from 'vitest'
+import { APP_SUBPROTOCOL, encodeTokenSubprotocol } from 'relay-contracts'
+import { readConfig } from '../src/config'
+import { createPassthroughTransport, type WebSocketLike } from '../src/ws-transport'
+
+const cfg = readConfig({
+  protocol: 'https:',
+  host: 'alice.term.example.com',
+  hostname: 'alice.term.example.com',
+})
+
+/** Controllable mock WebSocket capturing constructor args and driving lifecycle events. */
+class MockWs implements WebSocketLike {
+  static last: MockWs | null = null
+  binaryType = ''
+  protocol = ''
+  readonly url: string
+  readonly protocols: readonly string[]
+  readonly sent: Array<ArrayBufferView | ArrayBufferLike | string> = []
+  closed: { code?: number; reason?: string } | null = null
+  onopen: ((ev: unknown) => void) | null = null
+  onmessage: ((ev: { data: unknown }) => void) | null = null
+  onclose: ((ev: { code?: number; reason?: string }) => void) | null = null
+  onerror: ((ev: unknown) => void) | null = null
+
+  constructor(url: string, protocols?: string | readonly string[]) {
+    this.url = url
+    this.protocols = protocols === undefined ? [] : typeof protocols === 'string' ? [protocols] : protocols
+    MockWs.last = this
+  }
+  send(data: ArrayBufferView | ArrayBufferLike | string): void {
+    this.sent.push(data)
+  }
+  close(code?: number, reason?: string): void {
+    const ev: { code?: number; reason?: string } = {}
+    if (code !== undefined) ev.code = code
+    if (reason !== undefined) ev.reason = reason
+    this.closed = ev
+    this.onclose?.(ev)
+  }
+  fireOpen(echoedProtocol: string): void {
+    this.protocol = echoedProtocol
+    this.onopen?.({})
+  }
+  fireMessage(data: unknown): void {
+    this.onmessage?.({ data })
+  }
+}
+
+describe('createPassthroughTransport (T4)', () => {
+  it('v0.8: opens same-origin wss with NO query-string token (cookie-only auth)', async () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs })
+    const opened = t.open()
+    MockWs.last!.fireOpen(APP_SUBPROTOCOL)
+    await opened
+    expect(MockWs.last!.url).toBe('wss://alice.term.example.com/term')
+    expect(MockWs.last!.url).not.toMatch(/token|\?/)
+    expect(MockWs.last!.protocols).toEqual([APP_SUBPROTOCOL]) // no token entry in v0.8
+    expect(MockWs.last!.binaryType).toBe('arraybuffer')
+  })
+
+  it('round-trips bytes: send() reaches the socket, onMessage() delivers incoming bytes', async () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs })
+    const received: Uint8Array[] = []
+    t.onMessage((b) => received.push(b))
+    const opened = t.open()
+    MockWs.last!.fireOpen(APP_SUBPROTOCOL)
+    await opened
+
+    t.send(new Uint8Array([9, 8, 7]))
+    expect(MockWs.last!.sent[0]).toEqual(new Uint8Array([9, 8, 7]))
+
+    MockWs.last!.fireMessage(new Uint8Array([1, 2]).buffer)
+    expect(received[0]).toEqual(new Uint8Array([1, 2]))
+  })
+
+  it('v0.9+ token attachment: token rides Sec-WebSocket-Protocol, NEVER the URL (§4.3)', async () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs, capabilityToken: 'RAWTOK' })
+    const opened = t.open()
+    MockWs.last!.fireOpen(APP_SUBPROTOCOL)
+    await opened
+    expect(MockWs.last!.protocols).toEqual([APP_SUBPROTOCOL, encodeTokenSubprotocol('RAWTOK')])
+    expect(MockWs.last!.url).not.toContain('RAWTOK') // never in the URL/query
+    expect(MockWs.last!.url).not.toContain(encodeTokenSubprotocol('RAWTOK'))
+  })
+
+  it('v0.9+ echo rule: a token echo (or foreign subprotocol) tears the socket down', async () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs, capabilityToken: 'RAWTOK' })
+    const opened = t.open()
+    MockWs.last!.fireOpen(encodeTokenSubprotocol('RAWTOK')) // relay wrongly echoes the token entry
+    await expect(opened).rejects.toThrow()
+    expect(MockWs.last!.closed).not.toBeNull()
+  })
+
+  it('server close reason surfaces via onClose (no silent swallow)', async () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs })
+    let reason = ''
+    t.onClose((r) => (reason = r))
+    const opened = t.open()
+    MockWs.last!.fireOpen(APP_SUBPROTOCOL)
+    await opened
+    MockWs.last!.close(1000, 'shell exited')
+    expect(reason).toBe('shell exited')
+  })
+
+  it('a socket error during open rejects the open() promise', async () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs })
+    const opened = t.open()
+    MockWs.last!.onerror?.({})
+    await expect(opened).rejects.toThrow('websocket error')
+  })
+
+  it('close() before open() is a safe no-op (no throw)', () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs })
+    expect(() => t.close()).not.toThrow()
+  })
+
+  it('a 4403 upgrade denial maps to onClose("forbidden") (INV1/INV6 client mirror)', async () => {
+    const t = createPassthroughTransport(cfg, { wsCtor: MockWs })
+    let reason = ''
+    t.onClose((r) => (reason = r))
+    const opened = t.open()
+    MockWs.last!.fireOpen(APP_SUBPROTOCOL)
+    await opened
+    MockWs.last!.close(4403, '')
+    expect(reason).toBe('forbidden')
+  })
+})