Add MVP reconnect snapshots

Docs/MultiplayerNetworkingDesign.md

@@ -271,11 +271,14 @@ Initial latency testing should cover:
 
 MVP behavior:
 
-- disconnect removes the player's pawn from active control;
-- player survival/inventory can be preserved by the current persistence
-  mechanism if available;
-- reconnect may respawn the player at the last saved state or MVP spawn point,
-  depending on persistence maturity;
+- disconnect removes the player's pawn from active control and captures a
+  player reconnect snapshot during `AAgrarianGameGameMode::Logout`;
+- the reconnect snapshot preserves transform, survival, care history, and
+  inventory through `UAgrarianPersistenceSubsystem::SavePlayerSnapshot`;
+- reconnect/spawn restores the matching snapshot in
+  `AAgrarianGameGameMode::RestartPlayer` through
+  `UAgrarianPersistenceSubsystem::RestorePlayerSnapshot`;
+- if no matching snapshot exists, the player uses the normal MVP spawn point;
 - server should not crash or leak active interaction/build state when a player
   disconnects mid-action.