Design the Wikifunctions authoring experience for the Commons Image Data (Z300) type.
In scope:
- Z300 selector — lookup/search component for finding and selecting a Commons image by title or keyword; shows thumbnail preview in results
- Collapsed state (ZObjectToString) — how a Z300 value appears inside a collapsed function call (e.g. image icon + file title)
- Expanded state — full editor view with the current image selection and thumbnail preview
- Empty/unset state — "Select Commons image" CTA when no image is selected yet
Out of scope:
- How the rendered image figure appears in run-result views (separate design ticket)
- AW editor design (T423441)
