Add core service infrastructure

- NATS event bus (pub/sub, JetStream, KV storage)
- Service registry with health monitoring
- Base service class with lifecycle management
- Config system
- Logger with Vi formatting

Adapted from Lyra's patterns, namespace changed to vi.*

🦊💕

core/__init__.py

@@ -0,0 +1,31 @@
+# Vi Core Module
+# Nervous system infrastructure for Vivienne Rousseau
+
+from .config import config
+from .logger import setup_logger, logger
+from .nats_event_bus import NatsEventBus, nats_bus
+from .service_registry import (
+    ServiceRegistry,
+    ServiceManifest,
+    ServiceOperation,
+    ServiceInstance,
+    ServiceStatus,
+    service_registry
+)
+from .base_service import BaseService, SimpleService
+
+__all__ = [
+    'config',
+    'setup_logger',
+    'logger',
+    'NatsEventBus',
+    'nats_bus',
+    'ServiceRegistry',
+    'ServiceManifest',
+    'ServiceOperation',
+    'ServiceInstance',
+    'ServiceStatus',
+    'service_registry',
+    'BaseService',
+    'SimpleService',
+]