feat: add provenance-aware npc communication

docs/LEARNING_ROADMAP.md

@@ -668,16 +668,26 @@ The first witnessed-knowledge slice is also complete:
 - two equally familiar guards with different evidence now gain different trust
   and choose helping versus ordinary patrol;
 - the inspector resolves and displays the selected NPC's latest known fact;
-- schema v5 migration, invalid-reference rejection, deterministic save/load,
+- schema v6 migration, invalid-reference rejection, deterministic save/load,
   and proximity/idempotence tests cover the complete slice.
 
-This proves the first Milestone 6 evidence-to-choice exit path without claiming
-full memory or belief simulation. The practical next sequence is:
+The first communicated-knowledge slice is complete:
 
-1. Add acquisition provenance and one bounded NPC-to-NPC fact transfer so
-   information can travel beyond direct witnesses without replaying events.
-2. Add importance/retention rules for known facts before expanding into
-   distortion, secrecy, rumours, or opportunity generation.
+- first acquisition is persisted as performed, witnessed, communicated, or
+  legacy, with the direct speaker retained for communicated facts;
+- a villager arriving beside an already-working villager at a shared
+  non-storage activity can receive one newest direct fact within 2.5 metres;
+- communication references the original immutable event, changes only the
+  listener's knowledge/relationship consequence, and cannot relay a heard fact
+  again in this bounded phase;
+- the inspector names who communicated the fact, and schema-v6 migration,
+  malformed-provenance rejection, event-history invariance, save/checksum, and
+  informed-choice regressions cover the complete slice.
+
+This advances the first Milestone 6 evidence-to-choice path without claiming
+full memory or belief simulation. The practical next slice is importance and
+retention for known facts before expanding into distortion, secrecy, rumours,
+or opportunity generation.
 
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