refactor: remove dead is_breadcrumb parameter from _navigate_to_item_data (S-1)

The S3 fix removed the only conditional that read is_breadcrumb. Remove
the parameter from the signature and its kwarg from the one call site in
the breadcrumb button handler.

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

sharepoint_browser.py

@@ -1644,7 +1644,7 @@ class SharePointApp(wx.Frame):
             btn.Bind(wx.EVT_BUTTON, self.load_sites)
         elif data:
             def on_click(e, d=data):
-                self._navigate_to_item_data(d, is_breadcrumb=True)
+                self._navigate_to_item_data(d)
                 # Efter navigation, prøv at finde og vælge den i træet
                 wx.CallAfter(self._sync_tree_selection_by_path, d["path"])
                 
@@ -1853,7 +1853,7 @@ class SharePointApp(wx.Frame):
             
         self._navigate_to_item_data(data, tree_item=item)
 
-    def _navigate_to_item_data(self, data, tree_item=None, is_breadcrumb=False):
+    def _navigate_to_item_data(self, data, tree_item=None):
         try:
             # Race-condition beskyttelse: Hvis vi allerede er der, så stop
             if getattr(self, 'current_path', None) == data.get("path"):