feat: Add initial main game scene with grid map, player board UI, and manager scripts for game logic and input.

scripts/managers/playerboard_manager.gd

@@ -119,11 +119,13 @@ func _execute_grab(grid_pos: Vector2i, cell: Vector3i, item_id: int):
 	# Check if item is still there
 	if server_item != item_id:
 		print("Server: Item mismatch or already taken. Server has ", server_item)
+		_force_sync_to_client(cell, server_item)
 		return false
 	
 	# Check action points
 	if player.action_points <= 0:
 		print("Server: Player has no action points.")
+		_force_sync_to_client(cell, server_item)
 		return false
 	
 	# Check adjacency
@@ -131,12 +133,14 @@ func _execute_grab(grid_pos: Vector2i, cell: Vector3i, item_id: int):
 		var neighbors = server_gridmap.get_neighbors(player.current_position, 0)
 		if not neighbors.any(func(n): return n.position == grid_pos):
 			print("Server: Player is not adjacent to item.")
+			_force_sync_to_client(cell, server_item)
 			return false
 
 	# 2. Server-side Auto-Arrange
 	var target_slot = find_best_goal_slot_for_item(item_id)
 	if target_slot == -1:
 		print("Server: Player has no valid slot for item.")
+		_force_sync_to_client(cell, server_item)
 		return false
 
 	# 3. Server Executes the Action
@@ -197,6 +201,32 @@ func _check_and_refill_grid_if_needed(server_gridmap: Node):
 					var item = server_gridmap.get_cell_item(Vector3i(x, 1, z))
 					main.rpc("sync_grid_item", x, 1, z, item)
 
+
+
+func _force_sync_to_client(cell: Vector3i, server_item: int):
+	"""Force a sync of the specific cell and playerboard to the client who initiated the failed action."""
+	# Only meaningful if we are server
+	if not multiplayer.is_server():
+		return
+		
+	var main = player.get_tree().get_root().get_node_or_null("Main")
+	if not main: return
+	
+	# Determine client peer ID from player name (standard convention)
+	# Note: Bots are ID 1, so we don't need to sync special for them (local function calls)
+	# But for Clients...
+	var peer_id = player.name.to_int()
+	if peer_id == 1: # Server/Bot
+		return
+		
+	# Sync the Grid Item (which they thought they took)
+	main.rpc_id(peer_id, "sync_grid_item", cell.x, cell.y, cell.z, server_item)
+	
+	# Sync their Playerboard (which they thought they updated)
+	main.rpc_id(peer_id, "sync_playerboard", peer_id, player.playerboard)
+	
+	print("Server: Forced sync to client %d due to action failure." % peer_id)
+
 func bot_try_grab_item() -> bool:
 	if not enhanced_gridmap or player.action_points <= 0:
 		return false