feat(bus): complete TypeScript SDK — auth, room envelope, client, transport

Second half of the browser-native bus SDK (issue 0001, Phase 1), making uniweb a
peer of the bus in its own right (like unibus_android) without the Go gateway:

- busauth.ts: NATS user nkey from the Ed25519 key (base32 + crc16, no nkeys dep)
  and control-plane request signing (CanonicalRequest + X-Unibus-* headers).
- room.ts: Policy / Room types (ModeNATS, ModeMatrix).
- client.ts: the pure room ENVELOPE (sealRoomMessage/openRoomMessage — AEAD with
  the subject as AAD, Ed25519 sign, drop on verify/decrypt failure), a transport-
  agnostic BusClient, and a signed ControlPlane HTTP client (fetch room/key/members,
  open the sealed room key locally).
- wstransport.ts: concrete nats.ws WebSocket transport (validated E2E in Phase 3).
- index.ts: public SDK surface.

Parity pinned by vectors from unibus cmd/busvectors (extended with nkey + signed
control-request vectors): 19/19 green. The user's private key signs everything in
the browser and is never sent to any server. Bumps uniweb to 0.2.0.

Remaining for Phase 1 completion: the live nats.ws connection + control-plane,
which need a running unibus with the WebSocket listener — exercised in Phase 3.

app.md

@@ -2,7 +2,7 @@
 name: uniweb
 lang: go
 domain: infra
-version: 0.1.0
+version: 0.2.0
 description: "Frontend web del bus unibus: SPA de chat (React+Mantine) con wallet por usuario (BIP39) + gateway Go (REST+SSE) que actúa de peer del bus para el navegador."
 tags: [service, messaging, web, frontend, e2e]
 uses_functions:
@@ -118,6 +118,18 @@ programáticos) ve a `unibus`; `uniweb` solo es la capa web encima.
 
 ## Capability growth log
 
+- v0.2.0 (2026-06-13) — SDK del bus en TypeScript (`web/src/bus/`), issue 0001 Fase 1:
+  el protocolo y el cifrado E2E del bus portados al navegador para que `uniweb` deje
+  de depender del gateway Go. Módulos: `crypto.ts` (Ed25519, ChaCha20-Poly1305,
+  sealed box con nonce BLAKE2b igual que Go), `frame.ts` (wire format = `encoding/json`
+  de Go byte a byte), `room.ts` (Policy), `busauth.ts` (nkey NATS + firma de requests
+  del control-plane), `client.ts` (envelope de room puro + `BusClient` sobre una
+  interfaz de transporte + cliente HTTP firmado) y `wstransport.ts` (adaptador
+  `nats.ws`). Paridad cross-language verificada contra vectores Go (`cmd/busvectors`):
+  **19/19 tests verdes** — endpoint id, firma Ed25519, AEAD, sealed box, frame
+  marshal/sign, nkey y canonical request. La clave privada del usuario nunca se
+  serializa hacia la red. La conexión `nats.ws` + control-plane reales se validan en
+  la Fase 3 (E2E) por requerir un unibus vivo con WebSocket.
 - v0.1.0 (2026-06-13) — scaffold inicial: extracción de la SPA (`web/`) y el gateway
   (`cmd/webgw`) desde `unibus` v0.13.0 a su propia app/sub-repo. Sin cambios de capacidad
   respecto a lo que ya vivía en unibus 0.12.0 (wallet BIP39 + sesiones por usuario); solo