Provisioning: Deprecate folder move and delete on configured branch (#115329)

* Provisioning: Deprecate single file/folder move and delete on configured branch

Reject individual file and folder move/delete operations on the configured
branch via the single files endpoints (HTTP 405 MethodNotAllowed). Users
must use the bulk operations API (jobs API) instead.

Motivation:
- Reconciliation for these operations is not reliable as it must be
  recursive and cannot run synchronously since it could take a long time
- Simplifies authorization logic - fewer operations to secure and validate
- Reduces complexity and surface area for potential bugs
- Bulk operations via jobs API provide better control and observability

Operations on non-configured branches (e.g., creating PRs) continue to work
as before since they don't update the Grafana database.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

* fix: remove trailing whitespace in test file

* Fix behaviour to match current behavior

* Revert changes for individual files

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

pkg/tests/apis/provisioning/repository_test.go

@@ -786,7 +786,7 @@ func TestIntegrationProvisioning_ImportAllPanelsFromLocalRepository(t *testing.T
 	v, _, _ := unstructured.NestedString(obj.Object, "metadata", "annotations", utils.AnnoKeyUpdatedBy)
 	require.Equal(t, "access-policy:provisioning", v)
 
-	// Should not be able to directly delete the managed resource
+	// Should be able to directly delete the managed resource
 	err = helper.DashboardsV1.Resource.Delete(ctx, allPanels, metav1.DeleteOptions{})
 	require.NoError(t, err, "user can delete")