GitLab

Web UI / models:
- "To download" wishlist: models known but not on disk and not configured show
  as non-configured to-download rows. Free-disk on an unconfigured model, Remove
  on a model with no files left, and a new "Add to list" button in the download
  window all record into models.json `to_download`; pruned on enable/download.
  New endpoints model-mark-download / model-unmark-download.
- mmproj multimodal components: mmproj GGUFs are classified as components (not
  models), selectable per-GGUF in the model config (auto-selected, enables vision
  capability). VulkanBackend loads them via llama.cpp's MTMDChatHandler (--mmproj
  equivalent), and the chat path now forwards image_url content end-to-end.
- All window.alert() replaced by a shared styled showAlert()/showConfirm() modal
  in base.html (used across every admin template).

Front proxy / broker:
- Fix engine model-assignment NameError (keep -> _keep).
- Brokered ...