Fix: Add PlaceFromLoad and UnpackStage2 in ProcessBuildingHook

The hook was missing the critical World.inst.PlaceFromLoad() call which:
- Places building in world cells
- Sets up pathing data for villager navigation
- Registers building properly

Also added UnpackStage2() for complete building initialization.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Main.cs

@@ -1406,6 +1406,10 @@ namespace KCM
                         structureData.Unpack(building);
                         p.AddBuilding(building);
 
+                        // Place building in world and setup pathing
+                        World.inst.PlaceFromLoad(building);
+                        structureData.UnpackStage2(building);
+
                         Main.helper.Log($"Loading player id: {p.PlayerLandmassOwner.teamId}");
                         Main.helper.Log($"loading building: {building.FriendlyName}");
                         Main.helper.Log($" (teamid: {building.TeamID()})");