Add image labels for performer images

[Maista6969]

This PR provides two new features: performer images can be labeled and dated, and users of a stash-box can express their preferences for which images they'd like to see both when browsing and when scraping performers.

As discussed in #237 I opted for a closed taxonomy of types for the primary reason of compatibility: having a canonical set of labels for images means that users can use their preferences across multiple stash-boxes. Having users configure their preferences on the stash-box itself serves to simplify the rollout: if we had to rely on users configuring their preference in Stash then we'd need to coordinate releases, have Stash send an ordering whenever it scrapes a performer and also be more careful about backwards compatibility.

The taxonomy is intentionally wide because stash-box administrators can choose to disable the types they do not want to use for their labeling (maybe you think 3-quarters plus is excessive), and even disable entire groups (like dress because your instance doesn't have a lot of nude performers). When a label is disabled nothing is deleted: it is still present on any images that had it before the label was disabled, it is simply "inert" for the purposes of sorting images. Re-enabling the type brings the label back for all purposes.

There is an exception to the user-preferred ordering of images and that's search results, mostly because of their size: at such a small scale I believe we should prefer headshots since they stay readable at much smaller sizes. Performer images in search results will always use a face crop if the performer has one, otherwise it falls back to whatever it would have gotten before this feature was added. This affects the performer field in scene edit forms and the site-wide search in the top right corner of the app.

I believe this resolves:

• [RFC] Performer Image Categorization #237 - the primary motivation for this PR
• [Feature] Add the posibility to order performer images #161 - instead of making people vote for images this PR provides the users with their own personalized view, hopefully preventing (or at least mitigating) edit wars over which image is the "best" for a given performer
• [Feature] Add image categorization #203 - this PR does not add aspect ratio as a label for images because that can be derived from the image dimensions themselves
• [Feature] Include image guidelines directly on Stashbox #211 - this PR lays the groundwork for this but would be further enhanced by the addition of something like the "image bible" that TMDB has
• [Bug Report] Low quality Performer image prioritization #1205 - performer images are now sorted by their labels, then their date, then their aspect ratio and finally their height as a tiebreaker

For the reviewer(s):

This is a lot of code to review, so I've split the work into commits that can (hopefully) be reviewed in order. The very first commit adds new entries to .gitattributes to help GitHub know which files are autogenerated so that they'll be collapsed in the diff view by default. This won't help this PR but for future work it should be helpful.

I've added tests, integration tests and end-to-end playwright tests for this feature, and while they're bot-assisted I've seen each of them fail in my development environment so at least there are no duds in there.

AI Disclosure

I had Claude Opus look over the plan and assist with writing tests for this PR

Follow-up work

• [Feature] Add cropperjs to the add image section #212 - we can build a cropping UI on top of the "crop type" labels in this PR: if a user chooses the face crop label, we can immediately overlay a template with guidelines that help them crop the image to fit a common standard
• [Feature] Image voting system #436 - if we'd still like to add image voting that can easily be inserted into the sorting process