fix(network): prevent null multiplayer peer crashes offline/teardown and fix Nakama RPC session validation

scenes/player.gd

@@ -33,7 +33,7 @@ var display_name: String:
 
 # Helper to check network status
 func can_rpc() -> bool:
-	if not multiplayer.has_multiplayer_peer(): return false
+	if not is_inside_tree() or not multiplayer or not multiplayer.has_multiplayer_peer(): return false
 	if multiplayer.multiplayer_peer.get_class() == "OfflineMultiplayerPeer": return false
 	return multiplayer.multiplayer_peer.get_connection_status() == MultiplayerPeer.CONNECTION_CONNECTED
 	
@@ -81,7 +81,7 @@ var is_charged_strike: bool = false:
 		_refresh_player_visuals()
 			
 		# Sync to others if we are the authority
-		if is_multiplayer_authority() and can_rpc():
+		if is_inside_tree() and is_multiplayer_authority() and can_rpc() and multiplayer.has_multiplayer_peer():
 			rpc("sync_charged_strike", is_charged_strike)
 
 @rpc("any_peer", "call_local", "reliable")
@@ -219,8 +219,8 @@ func _ready():
 	# This prevents "grounding" friction and gravity from fighting our Tweens
 	motion_mode = CharacterBody3D.MOTION_MODE_FLOATING
 	
-	print("[Player] initialized: ", name, " Authority: ", get_multiplayer_authority())
-	# name = str(get_multiplayer_authority()) # CRITICAL FIX: Do NOT overwrite name. Bots have authority 1 but unique names (IDs).
+	var authority_id = get_multiplayer_authority() if multiplayer and multiplayer.has_multiplayer_peer() else 0
+	print("[Player] initialized: ", name, " Authority: ", authority_id)
 	# Look up player's display name from LobbyManager
 	var my_id = get_multiplayer_authority()
 	
@@ -255,7 +255,7 @@ func _ready():
 		var mat = ShaderMaterial.new()
 		mat.shader = pointer_shader
 			
-		if name == str(multiplayer.get_unique_id()):
+		if multiplayer and multiplayer.has_multiplayer_peer() and name == str(multiplayer.get_unique_id()):
 			mat.set_shader_parameter("pointer_color", Color(0.0, 1.0, 0.0, 1.0)) # Green
 			if has_node("Name"):
 				$Name.modulate = Color(0.2, 0.8, 0.2, 1.0) # Pleasant Green for Name
@@ -308,7 +308,7 @@ func _ready():
 				current_position = _find_random_spawn_position()
 				update_player_position(current_position)
 				spawn_point_selected = true
-				if can_rpc():
+				if can_rpc() and multiplayer.has_multiplayer_peer():
 					rpc("set_spawn_position", current_position)
 					rpc("notify_spawn_selected", current_position)
 		
@@ -318,11 +318,11 @@ func _ready():
 		var char_index = (bot_id_val - 1) % bot_characters.size()
 		var bot_char_name = bot_characters[char_index]
 		set_character(bot_char_name)
-		if is_multiplayer_authority() and can_rpc():
+		if can_rpc() and multiplayer.has_multiplayer_peer():
 			rpc("sync_character", bot_char_name)
 		
 		# Sync bot status to network
-		if is_multiplayer_authority() and can_rpc():
+		if can_rpc() and multiplayer.has_multiplayer_peer():
 			rpc("sync_bot_status", true)
 		
 		# Continue to manager initialization...
@@ -347,7 +347,7 @@ func _ready():
 			current_position.y * 1 + 1 * 0.5
 		)
 		target_visual_position = global_position
-		if is_multiplayer_authority() and can_rpc():
+		if can_rpc() and multiplayer.has_multiplayer_peer():
 			rpc("sync_position", current_position)
 	else:
 		target_visual_position = global_position
@@ -417,7 +417,9 @@ func play_scatter_knock():
 func play_playerboard_scatter():
 	"""Show the one-shot scatter VFX over the playerboard UI, but only on the
 	local human player's own client (the board UI belongs to them)."""
-	var is_local = name == str(multiplayer.get_unique_id())
+	var is_local = false
+	if multiplayer and multiplayer.has_multiplayer_peer():
+		is_local = name == str(multiplayer.get_unique_id())
 	var is_bot_check = is_bot or is_in_group("Bots")
 	if not is_local or is_bot_check:
 		return
@@ -672,7 +674,7 @@ func _setup_character() -> void:
 		return
 		
 	var character_name = "Masbro" # Default
-	var player_authority_id = get_multiplayer_authority()
+	var player_authority_id = get_multiplayer_authority() if multiplayer and multiplayer.has_multiplayer_peer() else name.to_int()
 	
 	# Look up character from LobbyManager for this player (works for all players)
 	if LobbyManager:
@@ -896,7 +898,9 @@ func sync_playerboard(new_playerboard: Array):
 	
 	# Only update UI if this is the LOCAL HUMAN PLAYER
 	# Bots managed by server (ID 1) might sync here, but we must NOT update UI for them
-	var is_local = name == str(multiplayer.get_unique_id())
+	var is_local = false
+	if multiplayer and multiplayer.has_multiplayer_peer():
+		is_local = name == str(multiplayer.get_unique_id())
 	var is_bot_check = is_bot or is_in_group("Bots")
 	
 	# DEBUG: Trace why UI updates might be happening
@@ -1376,7 +1380,7 @@ func _process(delta):
 	if LobbyManager.get_randomize_spawn() and spawn_point_selected and not visible:
 		visible = true
 
-	if not multiplayer.has_multiplayer_peer():
+	if not multiplayer or not multiplayer.has_multiplayer_peer():
 		return
 
 	if is_multiplayer_authority():
@@ -1478,7 +1482,7 @@ var last_sent_position: Vector3
 
 func _physics_process(delta):
 	# Sync position periodically (Heartbeat / Smoothing)
-	if not multiplayer.has_multiplayer_peer():
+	if not multiplayer or not multiplayer.has_multiplayer_peer():
 		return
 		
 	if is_multiplayer_authority():
@@ -2018,7 +2022,7 @@ func bot_try_grab_item() -> bool:
 		#if empty_slot == -1:
 			#return false
 			#
-		#if is_multiplayer_authority():
+		#if is_multiplayer_authority() and can_rpc() and multiplayer.has_multiplayer_peer():
 			#rpc("bot_grab_item", grid_position, empty_slot, cell.x, cell.y, cell.z)
 		#return true
 	#
@@ -2065,7 +2069,7 @@ func bot_try_grab_item() -> bool:
 		#return false  # no space
 #
 	## Perform the grab and auto-place
-	#if is_multiplayer_authority():
+	#if is_multiplayer_authority() and can_rpc() and multiplayer.has_multiplayer_peer():
 		## Update gridmap: remove item
 		#rpc("sync_grid_item", cell.x, cell.y, cell.z, -1)
 		## Update playerboard