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>

addons/godot_db_manager/core/database.gd

@@ -188,11 +188,11 @@ func is_dirty() -> bool :
 
 # serialization
 func save_db() -> void :
-	if(m_db_name.empty()):
+	if(m_db_name.is_empty()):
 		print("ERROR: GDDatabase::save_db() - current database doesn't have a name")
 		return
 
-	if(m_db_filepath.empty()):
+	if(m_db_filepath.is_empty()):
 		print("ERROR: GDDatabase::save_db() - current database doesn't have a path file")
 		return
 
@@ -257,7 +257,9 @@ func load_db() -> int :
 	file.open(get_db_filepath(), File.READ)
 	var content = file.get_as_text()
 	file.close()
-	var dictionary = JSON.parse(content).result
+	var test_json_conv = JSON.new()
+	test_json_conv.parse(content).result
+	var dictionary = test_json_conv.get_data()
 
 	# check the signature
 	if(!dictionary.has(gddb_constants.c_gddb_signature)):