Preferences: lazy loading on connect, on by default

Off reads the whole app from app.sab when connecting. Read at each connect, so a
change takes effect on the next one.

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

device_session.py

@@ -70,11 +70,14 @@ class DeviceSession:
         self._load_slot_registry(parts)
 
         self.sox_client.load(0)
-        try:
-            count = self.seed_from_sab()
-            self.seed_info = f"app read from app.sab: {count} components"
-        except Exception as e:
-            self.seed_info = f"app.sab not used: {e}"
+        if app_state.LAZY_LOADING:
+            self.seed_info = "lazy loading"
+        else:
+            try:
+                count = self.seed_from_sab()
+                self.seed_info = f"app read from app.sab: {count} components"
+            except Exception as e:
+                self.seed_info = f"app.sab not used: {e}"
 
         root_comp = self.sox_client.cache_get(0)
         if root_comp and root_comp.children: