feat: ADP Export Files menu with filestore storage, remove Sync All button

- Add fusion_claims.adp.export.record model with filestore-backed Binary field
  for tracking exported ADP claims files organized by Year > Month > Posting Period
- Add tree/form/search views with default group-by hierarchy, latest first
- Add "Export Files" menuitem under ADP menu section
- Add bulk ZIP download server action for multi-select export
- Replace Documents app storage with new model in export wizard
- Remove Documents-related methods (_save_to_documents, folder creation)
- Add migration button in Settings to move existing Documents files
- Fix Export ADP button visibility: only show on ADP portion invoices
- Remove redundant Sync All button from invoice form
- Add ACL entries for billing users (read/create) and managers (full CRUD)
- Bump version to 19.0.7.3.0

Made-with: Cursor

fusion_claims/models/res_config_settings.py

@@ -641,3 +641,7 @@ class ResConfigSettings(models.TransientModel):
     def action_set_gradient_dark_slate(self):
         self._apply_gradient_preset('dark_slate')
 
+    def action_migrate_adp_export_files(self):
+        """Migrate ADP export files from Documents app to the new Export Files menu."""
+        return self.env['fusion_claims.adp.export.record'].migrate_from_documents()
+