Fix song/application access: property not method call

ControlSurface exposes song and application as properties, not callable
methods. Replace manager.song() and manager.application() with the correct
attribute access throughout handler, application, browser, and view modules.

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

AbletonOSC/browser.py

@@ -46,7 +46,7 @@ class BrowserHandler(AbletonOSCHandler):
 
     def _browser(self):
         try:
-            return self.manager.application().browser
+            return self.manager.application.browser
         except Exception:
             return None