[Feature Request] Drag-and-drop layout editing mode in the in-app browser

What feature would you like to see?

Please add an optional Layout editing mode to the Codex in-app browser, alongside the existing annotation workflow.

When reviewing a local web prototype, the user should be able to:

• Drag and reorder complete cards or sections.
• Drag smaller UI blocks within a card to adjust their order or placement.
• Preview the proposed arrangement in the real page viewport.
• Save the resulting layout as structured review feedback that Codex can translate into source-code changes.
• Exit or reset the editing session without modifying the reviewed product itself.

A possible flow is:

1. Open a page in the in-app browser.
2. Choose Edit layout.
3. Drag components to the desired positions.
4. Choose Save layout.
5. Codex receives the changed hierarchy/order and updates the source after the user confirms the implementation.

This should be clearly presented as a temporary review tool, not as functionality added to the user's product.

Why this matters

Annotation is useful for identifying an element and describing a change, but layout feedback is often spatial. Explaining card order, internal information hierarchy, alignment, or relative placement through screenshots and text is slower and can be ambiguous.

A lightweight drag-and-drop review mode would let non-developer product and design users demonstrate the intended layout directly, reduce repeated clarification, and give Codex more precise implementation input.

Example use case

While reviewing a mobile web prototype, a user wants an order card to follow the layout of another existing card:

• store name and status at the top;
• icon, business name, page count, and amount in the body;
• order number at the bottom left;
• date at the bottom right.

The user could rearrange those blocks visually and save the arrangement instead of describing every positional change in prose.

Scope suggestion

A useful first version could support DOM-backed blocks and sortable flex/grid children on localhost or explicitly trusted preview pages. It does not need to become a general-purpose design editor; the key output is structured layout intent for Codex to implement in the real source.

Start by locating the Codex in-app browser and its existing annotation workflow, then map how review feedback is represented and passed to implementation. Define the first scope around trusted or localhost preview pages, DOM-backed blocks, and sortable flex/grid children. Done means users can enter, preview, save, reset, and exit a temporary layout session without changing the reviewed product directly.