The vision/video sidecar dropdown filtered candidates through the built-in
capability heuristics, so provider-compatible models whose custom names match
no known prefix (and carry no declared modalities) were hidden and could not be
selected as a sidecar — even when they natively support the modality.
- listByType now returns every enabled chat model, annotating each row with a
transient modalityCapable flag and sorting known-capable rows first, instead
of hard-filtering recognized models only.
- MultimodalRouter honours an explicitly configured sidecar model instead of
dropping it when the heuristics don't recognize it; a wrong pick degrades
gracefully through the caption path rather than silently disabling routing.
- ModelPicker gains an optional capability badge; the sidecar UI tags
recognized vision models while keeping every enabled model selectable.
