Use absolute path for editor.properties to avoid PermissionError

The relative path failed when the working directory differed from
the script directory at runtime.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app_state.py

@@ -9,7 +9,7 @@ import configparser
 import os
 
 VERSION = "0.0.0.028"
-PROPERTIES_FILE = "editor.properties"
+PROPERTIES_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "editor.properties")
 DEFAULT_GRID_SIZE = 10
 DEFAULT_ADD_TIMESTAMP = True