Fix world population race and add multiplayer diagnostics

The world was populated before NetworkManager.world_ready() actually
called host()/join(), so owns_world() read true for every peer
(including a joining client) and each one built its own local,
unreplicated copy instead of the client receiving the server's spawn
through the MultiplayerSpawner. Population now happens after the
session is actually established.

Also adds net-log coverage for spawn/despawn, station gating, item
authority handoff, station snapping, avatar spawn/despawn, and scene
transitions, so multiplayer behavior is visible in
%TEMP%\vryhungry_net_<pid>.log instead of failing silently.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Scenes/multiplayer_world.gd

@@ -31,11 +31,27 @@ func _ready() -> void:
 	NetworkManager.session_ended.connect(_on_session_ended)
 	NetworkManager.connection_failed.connect(_on_connection_failed)
 
-	# Offline (single player / dev run): owns_world() is already true, so
-	# populate immediately. Online host case is handled by session_started.
+	# world_ready() is what actually calls host()/join() (or the cmdline
+	# equivalent). Populating before this point is wrong for EVERY case, not
+	# just offline: is_online() is still false until host()/join() runs, so
+	# owns_world() would read true for a joining client too, and it would
+	# build its own local copy instead of receiving the server's via the
+	# spawner. host() emits session_started synchronously, which populates
+	# via _on_session_started below; the explicit call after world_ready()
+	# only matters for the case where neither host() nor join() ran (no
+	# pending session, no cmdline args) — running this scene directly offline.
+	NetworkManager.world_ready()
 	_populate_world_if_owner()
 
-	NetworkManager.world_ready()
+	get_tree().create_timer(3.0).timeout.connect(_log_world_state)
+
+
+# Temporary-ish sanity check: confirms WorldContent actually ended up
+# populated on this peer (whether by spawning it or by receiving it via
+# replication), so a silent replication failure shows up in the net log
+# instead of just an empty-looking world.
+func _log_world_state() -> void:
+	NetworkManager.log_line("World state: WorldContent=%d children, Players=%d children" % [$WorldContent.get_child_count(), $Players.get_child_count()])
 
 
 func _exit_tree() -> void:
@@ -53,10 +69,14 @@ func _populate_world_if_owner() -> void:
 		return
 	_populated = true
 	GameManager.meals_in_play = ["hamburger"]
-	for d in WorldLayout.get_stations():
+	var stations := WorldLayout.get_stations()
+	var items := WorldLayout.get_items()
+	NetworkManager.log_line("Populating world: %d stations, %d items" % [stations.size(), items.size()])
+	for d in stations:
 		NetworkManager.spawn_item(d["scene"], d["xform"], d["name"], d["props"])
-	for d in WorldLayout.get_items():
+	for d in items:
 		NetworkManager.spawn_item(d["scene"], d["xform"], d["name"], d["props"])
+	NetworkManager.log_line("World populated")
 
 
 ## Only the server (or the single offline machine) materialises player
@@ -68,6 +88,7 @@ func _on_player_joined(peer_id: int) -> void:
 	var p := PLAYER_SCENE.instantiate()
 	p.name = str(peer_id)
 	$Players.add_child(p, true)
+	NetworkManager.log_line("Spawned avatar for peer %d" % peer_id)
 
 
 func _on_player_left(peer_id: int) -> void:
@@ -76,11 +97,14 @@ func _on_player_left(peer_id: int) -> void:
 	var p := $Players.get_node_or_null(str(peer_id))
 	if p:
 		p.queue_free()
+		NetworkManager.log_line("Despawned avatar for peer %d" % peer_id)
 
 
 func _on_session_ended() -> void:
+	NetworkManager.log_line("Session ended, returning to main menu")
 	get_tree().change_scene_to_file("res://Scenes/mainMenu.tscn")
 
 
 func _on_connection_failed() -> void:
+	NetworkManager.log_line("Connection failed, returning to main menu")
 	get_tree().change_scene_to_file("res://Scenes/mainMenu.tscn")