Sprint 1: runtime package init

purpose_agent/runtime/__init__.py

@@ -0,0 +1,14 @@
+"""
+Purpose Agent Runtime — Event-driven execution engine for v3.0.
+
+Provides:
+  - PAEvent: canonical event schema
+  - EventKind: enumerated event types
+  - EventBus: async pub/sub with backpressure and replay
+  - Checkpointer: durable state snapshots (Sprint 2)
+  - RunState: typed execution state (Sprint 2)
+"""
+from purpose_agent.runtime.events import PAEvent, EventKind, Visibility
+from purpose_agent.runtime.event_bus import EventBus
+
+__all__ = ["PAEvent", "EventKind", "Visibility", "EventBus"]