v2.14.4

v2.14.4: model icons come from model management, not name keywords

- Model icons in the usage logs, the pricing table view and the personal
  model list are no longer guessed from keywords in the model name. Any name
  that merely contained a vendor word was mislabelled — muse-spark-1.3-contributor
  showed the iFlyTek Spark icon while model management assigns it to the Meta
  vendor.
- The icon now resolves the same way the model management list and the pricing
  card view already resolve it: the model's own icon first, then its vendor's
  icon, and no icon at all when neither is configured.
- New GET /api/model_icons serves those rules to logged-in users, and the
  frontend matches exact model names before prefix, suffix and contains rules,
  mirroring how pricing expands model metadata.