Split embedding model validation message: checklist keeps full
"Embedding model not configured" while node inline row uses short
"Not configured" since the left label already says "Embedding model".
Also keep the row label color as tertiary gray instead of warning yellow.
Extract validation logic from default.ts into shared utils.ts, enabling
node card, panel, and checklist to share the same validation rules.
Introduce provider-scoped model list queries to detect non-active model
states (noConfigure, quotaExceeded, credentialRemoved, incompatible).
Expand node card from 2 rows to 4 rows with per-row warning indicators,
and add warningDot support to panel field titles.
