Run godot --convert-3to4 (automated conversion)

Apply Godot 4.6 automated conversion: renames Spatial.translate->position,
margin_*->offset_*, tool->@tool, .empty()->.is_empty(), DynamicFont->FontFile,
onready->@onready, export()->@export, and many more.

127 files changed by the tool. Manual fixes still required for:
 - godot_db_manager plugin (incompatible APIs: WindowDialog, Tabs, etc.)
 - lod plugin (Spatial -> Node3D renames)
 - ResourceLoader.load_interactive removed -> load_threaded_request
 - OS.set_window_fullscreen removed -> DisplayServer
 - Viewport.set_size_override removed

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

assets/props/parchment/parchment.gd

@@ -1,10 +1,10 @@
-tool
-extends Spatial
+@tool
+extends Node3D
 
-export(bool) var paper
+@export var paper: bool
 
 func activatePaper(showPaper):
-	if Engine.editor_hint:
+	if Engine.is_editor_hint():
 		paper = showPaper
 	
 	# var parent = get_node(".").name