sprint-5: NMEA 2000 stub + Log Book naval básico

vmssailor/runtime/server/nmea2000.py
- PgnFrame dataclass + parsers/encoders para PGNs clave:
  - 127257 Attitude (yaw/pitch/roll en radianes)
  - 127488 Engine Parameters Rapid (RPM, boost, trim)
  - 127489 Engine Dynamic (oil, coolant, alternator, hours)
  - 127505 Fluid Level (tanks)
  - 127508 Battery Status
  - 129025 Position Rapid
- N2KPublisher: tag updates -> PGNs publicados via transport callable
  - Sprint 5: callable de testing/observabilidad
  - Sprint 12+: integracion real con python-can / Actisense / YDWG-02
- N2KSubscriber: inyecta PGNs entrantes y los traduce a tag updates
  - PGN_ATTITUDE -> VESSEL.ROLL_DEG / VESSEL.PITCH_DEG (PGN 127257 = AR-ECDIS source)
  - PGN_ENGINE_RAPID -> ME_INST_{N}.RPM

vmssailor/runtime/server/logbook.py
- LogBook con cadena SHA-256 inmutable (prev_hash -> hash chain)
- LogEntryKind: ENGINE_START, ENGINE_STOP, ALARM_ACTIVE/ACK/CLEARED,
  AUTHORITY_TRANSFER, OVERRIDE, SNAPSHOT, MANUAL
- verify_chain() detecta tampering (bit flip o reescritura)
- query() con filtros por kind/since/until/limit
- EngineLogWriter: auto-detecta start/stop via cruces de umbral RPM
  con persistencia configurable (default 5s)
- SnapshotLogWriter: snapshots periodicos (default 15 min) condicional
  a motor corriendo

API actualizada:
- GET /logbook con filtros
- POST /logbook (entrada manual)
- GET /logbook/verify (integridad de cadena)

RuntimeApp integra todos los servicios. El alarm engine ahora
auto-anota al log book via callback con strong-ref task tracking.

Tests (tests/runtime/, 10 nuevos, total 152/152):
- test_logbook: append, chain, tamper detection, engine start/stop,
  snapshot writer con/sin motor corriendo
- test_nmea2000: PGN encode/decode roundtrip, publisher emits engine
  rapid frames, subscriber handles attitude

152/152 pytest verde, ruff clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

vmssailor/runtime/server/api.py

@@ -145,6 +145,69 @@ def create_app(runtime: RuntimeApp) -> FastAPI:
             raise HTTPException(status_code=404, detail=f"Alarma '{alarm_id}' no activa.")
         return acked.model_dump(mode="json")
 
+    # ----- Log Book ----------------------------------------------------
+
+    @app.get("/logbook")
+    def logbook_entries(
+        kind: str | None = None,
+        since: str | None = None,
+        until: str | None = None,
+        limit: int = 200,
+    ) -> list[dict[str, Any]]:
+        from vmssailor.runtime.server.logbook import LogEntryKind
+
+        kind_enum = LogEntryKind(kind) if kind else None
+        since_dt = datetime.fromisoformat(since) if since else None
+        until_dt = datetime.fromisoformat(until) if until else None
+        entries = runtime.logbook.query(
+            kind=kind_enum, since=since_dt, until=until_dt, limit=limit
+        )
+        return [
+            {
+                "id": e.id,
+                "kind": e.kind.value,
+                "timestamp": e.timestamp.isoformat(),
+                "summary": e.summary,
+                "payload": e.payload,
+                "user": e.user,
+                "hash": e.hash[:16] + "…",
+            }
+            for e in entries
+        ]
+
+    @app.post("/logbook")
+    def logbook_append_manual(
+        kind: str = "manual",
+        summary: str = "",
+        user: str = "operator",
+    ) -> dict[str, Any]:
+        import asyncio
+
+        from vmssailor.runtime.server.logbook import LogEntryKind
+
+        try:
+            kind_enum = LogEntryKind(kind)
+        except ValueError as err:
+            raise HTTPException(status_code=400, detail=f"Kind inválido: {kind}") from err
+        if not summary:
+            raise HTTPException(status_code=400, detail="summary requerido")
+
+        async def _do_append():
+            return await runtime.logbook.append(kind_enum, summary, user=user)
+
+        entry = asyncio.run_coroutine_threadsafe(_do_append(), asyncio.get_event_loop()).result(timeout=2)
+        return {
+            "id": entry.id,
+            "kind": entry.kind.value,
+            "timestamp": entry.timestamp.isoformat(),
+            "hash": entry.hash,
+        }
+
+    @app.get("/logbook/verify")
+    def logbook_verify() -> dict[str, Any]:
+        ok, broken = runtime.logbook.verify_chain()
+        return {"ok": ok, "broken_entry_ids": broken}
+
     # ----- WebSocket ---------------------------------------------------
 
     @app.websocket("/ws/realtime")