WP-0004: ecosystem integration complete

Add Helix Forge correlation (HELIX_SESSION_UID env, metrics correlate),
artifact-store publish (metrics publish), activity-core ActivityDefinition
references, integration patterns docs, and canon/knowledge design artifacts.

src/kaizen_agentic/integrations/__init__.py

@@ -0,0 +1,10 @@
+"""Ecosystem integration adapters (Helix Forge, artifact-store)."""
+
+from .artifact_store import publish_optimizer_evidence
+from .helix import HelixCorrelationAdapter, enrich_helix_correlation
+
+__all__ = [
+    "HelixCorrelationAdapter",
+    "enrich_helix_correlation",
+    "publish_optimizer_evidence",
+]