feat(shipote): audit log persistente + HTTP gateway (fase S)

- Daemon escribe append-only a $XDG_STATE_HOME/shipote/audit.log además
  del tracing. Single-line: ts=<ms> uid=<peer> action=<verb> <detail>.
  Rotación simple a .log.1 al pasar 1 MiB.
- shipote-gateway: TCP listener 127.0.0.1:7378 default. POST /rpc traduce
  JSON ↔ postcard contra daemon socket. GET / health text. HTTP parser
  ad-hoc (~70 LOC), sin dep de hyper/axum. Sin auth — bind a localhost
  + SHIPOTE_TRUST_ANYONE=1 en prod.

E2E: curl --noproxy '*' POST /rpc → "Pong", Health JSON, Capabilities
JSON. Audit log persiste mutaciones con uid del peer.

85 tests pasan (features nuevos son binarios, no library mods).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Cargo.lock

@@ -9661,6 +9661,18 @@ dependencies = [
  "toml 0.8.23",
 ]
 
+[[package]]
+name = "shipote-gateway"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "serde_json",
+ "shipote-protocol",
+ "tokio",
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "shipote-protocol"
 version = "0.1.0"