Two textually-clean but semantically-broken merges:
- routes.py lost its folder_paths import when #14796's import block
superseded the base's, while the content-type hardening added via the
base's master merge still calls folder_paths.is_dangerous_content_type.
- master's SVG download-hardening test uploads with the pre-namespacing
bare checkpoints tag, which this branch's destination validation
rejects; use model_type:checkpoints.
49b364887b