[ENG-46316] feat(webkit): add PickList (data)

[HerbertJulio]

Summary

New PickList (data) — a dual-list transfer control (source ↔ target) with move-selected / move-all controls in both directions and optional reorder.

API

• v-model modelValue: [source[], target[]] + update:modelValue.
• Props: dataKey, sourceHeader / targetHeader (default ''), disabled, reorderable.
• Events: update:modelValue, move {direction, items}, reorder {list, items}.
• Slots: item (scoped), sourceHeader, targetHeader.
• Move/reorder controls use crisp inline SVG arrows (themeable via currentColor, accessible).

Notes — needs design validation (no Figma reference existed)

• The API was rewritten from the PrimeVue PickList to our conventions; the visual surface (3-column grid, sizing/placement) is a first draft and should be reviewed by design.
• Reorder is target-list-only; header slot names are camelCase (#sourceHeader) due to a hook slot-parser constraint.
• Draft — pending review. Spec .specs/pick-list.md (approved). Flat export ./pick-list.