BURST pattern tweak

[Salominius]

Describe the bug
My Honor 20 Pro follows Fairphone/Motorola pattern for burst images. However, while the default gallery allows any string in front of the "_BURST" ending, as long as it is the same for the whole series, this isn't the case in Aves.

To Reproduce

1. Select burst pattern "Fairphone, Motorola"
2. Save 2 images as
   "IMG_20251231_115959_BURST001_COVER"
   "IMG_20251231_115959_BURST002"
3. Verify that burst view works. Then remove the "IMG_" prefix from the two filenames.
4. At this point the burst series is not recognized anymore.

Expected behavior
Removing "IMG_" should not break the burst view. Generally, the ending _BURST\d{3}(_COVER)? should be the only thing checked here. (Obviously still assuming that the image names of a burst series only differ in that ending and are otherwise identical).

Additional context
Feel free to reach out to me for any more information or clarification.

[deckerst]

Why would you rename the files to remove the prefix? Or is it that your device creates files without this prefix?

More generic patterns may make the check computationally more expensive. That's why the current patterns are constrained the way they are. I'm open to pattern additions/changes if the devices/cameras create files with that pattern. Any subsequent renaming becomes the user responsibility.

[Salominius]

I have a collection of photos from various cameras and use a script to standardize their names for consistency and sorting purposes.

The IMG_ prefix only really makes sense if one wants to distinguish images and videos - which I don't. And even if I did, there's plenty of other ways to do so.

From a computational perspective, relaxing the pattern should not meaningfully impact performance, since the algorithm only needs to evaluate the trailing segment of the filename for the _BURST suffix. I'd expect prefix length or content to be irrelevant as long as matching is anchored near the end.

If you still think its an issue, maybe keeping the existing patterns as they are and adding a new option with "relaxed prefix" would be a good solution.
Either way, the change would enhance robustness and keep the way the gallery behaves more in line with pre-installed gallery-implementations, allowing more flexibility when storing files in a different naming pattern.