feat: add provenance-aware npc communication

docs/BUILD_IN_PUBLIC_PLAN.md

@@ -689,12 +689,17 @@ Completed:
 21. Witnessed event knowledge: objective food-deposit events create separate
     known-event references for their actor and nearby living NPCs. Knowledge
     gates trust, produces a real informed-versus-uninformed choice divergence,
-    survives schema-v5 save/load, and appears in the NPC inspector.
+    survives versioned save/load, and appears in the NPC inspector.
+22. Co-worker fact communication: known-event records retain performed,
+    witnessed, communicated, or legacy acquisition provenance. An arriving NPC
+    can hear one direct fact from a nearby worker at the same non-storage
+    activity; the inspector names the speaker, the original event is not
+    replayed, and heard facts do not cascade yet.
 
 Next:
 
-1. Add one provenance-aware NPC-to-NPC fact transfer, then bounded
-   importance/retention rules, as sequenced in `LEARNING_ROADMAP.md`.
+1. Add bounded importance/retention rules for known facts, as sequenced in
+   `LEARNING_ROADMAP.md`.
 
 Do not start with GIS data, a full city, a large asset pack, or more NPC
 mechanics. The next proof is a beautiful stage for the systems that already