Add minimum image width to download options

[jamesmisson]

This adds a minImageWidth config option to the download dialogue that checks for a minimum image width before offering the option to download the image.

It gets the maxWidth as usual, then checks this against the minImageWidth. If the maxWidth is greater than the minImageWidth, it gets displayed as a download option. If it's smaller, no download is allowed.

E.g. this manifest has a maxWidth of 512 on the images and needs download restricted according to the item's RAQ ID: https://stage.bl.digirati.io/manifests/ark:/81055/vdc_100170823639.0x000001

Setting the download dialogue options to the following will display the 'no download available' message in the download dialogue:

{
  "modules": {
    "downloadDialogue": {
      "options": {
        "minImageWidth": 513
      }
    }
  }
}

[vercel]

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Project	Deployment	Actions	Updated (UTC)
universalviewer	Ready	Preview, Comment	Apr 2, 2026 3:37pm

[vercel]

@jamesmisson is attempting to deploy a commit to the Universal Viewer Team on Vercel.

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[demiankatz]

Thanks, @jamesmisson, see below for a few suggestions (one stylistic, the other perhaps slightly more significant). In any case, nitpicks aside, this makes sense to me in principle!

[demiankatz]

Thanks, @jamesmisson, the logic fixes look good -- now we just need to agree on the best solution for the constant. I'm really fine with either of my proposed approaches, but I think we should do one or the other.

[demiankatz]

Code all looks good now, but it occurs to me that we need to add this to manual/CONFIG.md to keep the documentation up to date! Do you mind doing that before we merge this?

[jamesmisson]

Good point, thanks @demiankatz

[demiankatz]

This looks ready to go now!