Add a Properties view for the app root

The root tree row now names the app component, "app (<host:port>)" or
"app (<file>)", and offers Properties from its context menu and on
double-click. The live DOM's <app> element now carries its type and slot
values, and the refresh-by-id lookup finds it, so the view shows real
sys::App values.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app_state.py

@@ -8,7 +8,7 @@ so later rebinding would only ever be seen by the module that did it.
 import configparser
 import os
 
-VERSION = "0.0.0.134"
+VERSION = "0.0.0.135"
 PROPERTIES_FILE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "editor.properties")
 DEFAULT_GRID_SIZE = 10
 DEFAULT_ADD_TIMESTAMP = True