Preserve native chat during terrain takeover with fallback for missing chat

docs/terrain-takeover.md

@@ -240,8 +240,12 @@ account admission. Publication and live-server changes remain with the owner.
 - The private `Prefabs/ERR/TerrainTakeover.et` triggers client cleanup. It releases
   only the captured original singleton components, waits for the new factions
   before catalog/identity initialization, and receives the server's faction
-  delegates. Chat is replicated to every client. The ordinary authored connector
-  remains separate from this bootstrap.
+  delegates. The terrain's native chat service is retained on both peers, detached
+  from any removed entity/replication parent, and never replaced or attached to
+  the new mode. The ordinary authored connector retains its own chat service.
+  If the terrain has no chat service, `TerrainTakeoverWithChat.et` supplies a
+  non-streaming replicated chat child instead. Selection depends on service
+  presence, not terrain name; both variants share the same takeover mode.
 - Arsenal, group, support-station and task managers release the original mode's
   cached instances on both peers. Task, map-marker and respawn getters resolve
   the current takeover mode even if an old destructor clears a shared cache.
@@ -260,6 +264,18 @@ account admission. Publication and live-server changes remain with the owner.
   a separate connected Windows client. The connected test recreates the player's
   controller and verifies the replacement managers in both rounds.
 
+On 14 October, the original Everon client log showed delayed removal of the
+original `ScriptedChatEntity` after the replacement registered, followed by
+`Cannot send message - ChatEntity is missing.` This blocked native chat commands,
+including administrator login, before authentication. `test_terrain_chat_retention.py`
+checks shared-service retention, nested parent detachment and fallback selection.
+The revised scripts compiled in Workbench; the authored-world native restart
+smoke completed two rounds and 21 assertions with no script/runtime failures.
+That run still reported existing engine/dependency errors, and the full repository
+check stopped on the existing missing root ID in `ERRM_AtlasLeaf.et`.
+Live remote login and takeover of both chat variants remain separate verification
+steps; the authored-world smoke does not exercise those paths.
+
 The earlier isolated prototype passed a Nogova Workbench prisoner-spawn test with
 16 generated sites and zero script errors. See
 [prototype evidence](evidence/scenario-takeover-2026-10-01/report.json). The current