Update disconnect handling in App:startSession to show notification on disconnect

- Modified the logic to display a notification when the app disconnects from a session, improving user awareness of connection status.

plugin/src/App/init.lua

@@ -695,14 +695,16 @@ function App:startSession()
 					text = tostring(details),
 					timeout = 10,
 				})
-		else
-			self:setState({
-				appStatus = AppStatus.NotConnected,
-				toolbarIcon = Assets.Images.PluginButton,
-			})
-			-- Intentionally not showing a notification here to avoid
-			-- Studio switching focus to the viewport on disconnect
-		end
+			else
+				self:setState({
+					appStatus = AppStatus.NotConnected,
+					toolbarIcon = Assets.Images.PluginButton,
+				})
+				self:addNotification({
+					text = "Disconnected from session.",
+					timeout = 10,
+				})
+			end
 		end
 	end)