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.

term-relay/data-plane/config.ts

@@ -0,0 +1,81 @@
+/**
+ * T1 · Data-plane config — env → frozen DataPlaneConfig (INV9 fail-fast, no secret logged).
+ *
+ * Startup MUST fail if TLS server material, the AGENT_CA_CERT_PATH mTLS trust-anchor, or
+ * BASE_DOMAIN is absent (a missing CA would silently degrade "mTLS" to accept-any-cert,
+ * Finding-4). Zod validates at the boundary; the returned object is frozen (immutable).
+ */
+import { z } from 'zod'
+
+const MAX_FRAME_BYTES_DEFAULT = 1024 * 1024 // 1 MiB (§4.1 payloadLen ceiling)
+const INITIAL_WINDOW_BYTES_DEFAULT = 256 * 1024 // 256 KiB (§4.1 credit window)
+const HEARTBEAT_INTERVAL_MS_DEFAULT = 15_000 // §4.1: PING every 15s
+const ROUTE_TTL_MS_DEFAULT = 45_000 // Redis route:{host_id} TTL
+const BIND_HOST_DEFAULT = '0.0.0.0'
+const BIND_PORT_DEFAULT = 8443
+const AGENT_BIND_PORT_DEFAULT = 8444
+
+export interface DataPlaneConfig {
+  readonly baseDomain: string
+  readonly bindHost: string
+  readonly bindPort: number
+  readonly agentBindPort: number
+  readonly tlsCertPath: string
+  readonly tlsKeyPath: string
+  readonly agentCaCertPath: string
+  readonly agentCaChainPath: string
+  readonly relayNodeId: string
+  readonly maxFrameBytes: number
+  readonly initialWindowBytes: number
+  readonly heartbeatIntervalMs: number
+  readonly routeTtlMs: number
+}
+
+const requiredPath = z.string().min(1)
+const port = z.coerce.number().int().gt(0).max(65535)
+const positiveInt = z.coerce.number().int().positive()
+
+const ConfigSchema = z.object({
+  baseDomain: z.string().min(1),
+  bindHost: z.string().min(1).default(BIND_HOST_DEFAULT),
+  bindPort: port.default(BIND_PORT_DEFAULT),
+  agentBindPort: port.default(AGENT_BIND_PORT_DEFAULT),
+  tlsCertPath: requiredPath,
+  tlsKeyPath: requiredPath,
+  agentCaCertPath: requiredPath,
+  agentCaChainPath: requiredPath,
+  relayNodeId: z.string().min(1),
+  maxFrameBytes: positiveInt.default(MAX_FRAME_BYTES_DEFAULT),
+  initialWindowBytes: positiveInt.default(INITIAL_WINDOW_BYTES_DEFAULT),
+  heartbeatIntervalMs: positiveInt.default(HEARTBEAT_INTERVAL_MS_DEFAULT),
+  routeTtlMs: positiveInt.default(ROUTE_TTL_MS_DEFAULT),
+})
+
+/**
+ * Load + validate the data-plane config from `env`. Throws a clear, secret-free error
+ * (fail-fast, INV9) when a required key is missing or a numeric key is non-numeric.
+ * `agentCaChainPath` falls back to `agentCaCertPath` when unset (single-tier CA).
+ */
+export function loadDataPlaneConfig(env: NodeJS.ProcessEnv): DataPlaneConfig {
+  const parsed = ConfigSchema.safeParse({
+    baseDomain: env.BASE_DOMAIN,
+    bindHost: env.BIND_HOST,
+    bindPort: env.BIND_PORT,
+    agentBindPort: env.AGENT_BIND_PORT,
+    tlsCertPath: env.TLS_CERT_PATH,
+    tlsKeyPath: env.TLS_KEY_PATH,
+    agentCaCertPath: env.AGENT_CA_CERT_PATH,
+    agentCaChainPath: env.AGENT_CA_CHAIN_PATH ?? env.AGENT_CA_CERT_PATH,
+    relayNodeId: env.RELAY_NODE_ID,
+    maxFrameBytes: env.MAX_FRAME_BYTES,
+    initialWindowBytes: env.INITIAL_WINDOW_BYTES,
+    heartbeatIntervalMs: env.HEARTBEAT_INTERVAL_MS,
+    routeTtlMs: env.ROUTE_TTL_MS,
+  })
+  if (!parsed.success) {
+    // Report only WHICH keys are wrong — never echo values (INV9: no secret in logs).
+    const fields = parsed.error.issues.map((i) => i.path.join('.')).join(', ')
+    throw new Error(`invalid data-plane config: ${fields}`)
+  }
+  return Object.freeze(parsed.data)
+}