[FEATURE] Design canvas: reorder pages — the Pages menu is append-only (switch/rename/new only)

What I'm asking for

Let me change the order of pages in a Claude Design canvas artifact. Today pages are effectively append-only: the order they were created in is the order they stay in, forever.

Why it matters

A canvas that lives for more than a few days accumulates pages in creation order, which quickly stops matching the order a reader should see them in. Mine is a real example — a private canvas ("Rep Commission Screens", artifact 19bdd1e1-1468-4dfb-a035-7385e55b37de) whose pages are, in this order:

1. Views - v1
2. Models & Notes
3. Views - v2
4. Component Library

Views - v2 supersedes Views - v1, so the page anyone should open first is third in the list, and the superseded one greets every viewer. I can rename pages to fake a sort order ("1. …", "2. …"), but that is a workaround that pollutes the names and still doesn't move them.

The same shape shows up any time a canvas evolves: a new revision of the screens, an appendix that should sit last, a summary page added late that belongs first.

Current behaviour (verified against the shipped editor)

The Pages menu (data-testid="dc-pages") renders, per page, exactly two things — select/switch, and rename (data-testid="dc-page-rename") — plus a single New page action at the bottom. There is no move, drag handle, "send to end", or delete. Searching the bundle for Move page / Move up / Move down / Delete page / Duplicate page returns nothing; the only reordering code in the editor is z-order of elements inside an artboard, not pages.

Why this looks cheap to add

The underlying mutation already exists. Both "New page" and "Rename page" commit through the same history entry shape — {kind: "pages", from: <old array>, to: <new array>} — and the undo/redo handler for kind === "pages" simply swaps the whole pages array wholesale and persists it. A reorder is that identical mutation with a permuted array, so persistence and undo/redo should come for free. What's missing is only the affordance.

Suggested shape (in rough order of preference)

1. Drag-to-reorder the rows in the Pages menu.
2. Failing that, "Move up" / "Move down" next to the existing rename control — one more button in a menu row that already has one.
3. Either way, the reorder should persist to the saved canvas the same way a rename does, and be undoable.

Two smaller things worth folding in if they're easy, since the menu row is being touched anyway: delete a page, and duplicate a page. Neither exists today either.

What I'm doing instead right now

Re-seeding the whole canvas from its source files with pages in a different order. That's not a workaround so much as a rebuild — it regenerates the artboards and throws away anything I refined by hand in the editor, which is precisely the work the visual editor exists to make possible. A two-second drag shouldn't cost a full re-seed.

Environment

• Surface: Claude Design canvas published as an Artifact, viewed at claude.ai/code/artifact/…
• Claude Code CLI on macOS (Darwin 24.6.0)
• Canvas page limit observed in the bundle: 40 pages