Lataa Hydrus Network v659

misc
- certain PNGs that would load very slowly now load about ten times faster! specifically, any PNG with gamma/chromaticity information in its header now has that converted to a bespoke ICC Profile, and the normal ICC Profile translation code is applied to convert to sRGB. my hacky (and possibly unstable) manual conversion is no longer used. typically, a big ~50 megapixel PNG (7,000x8,000) would render in about ten seconds with lots of memory churn; now it renders in one, with far less. this fix brought to you by ChatGPT, which understands ICC Profile header construction, r/g/bTRC gamma curves, and D50/D65 wtpt and chad applicability across ICC Profile engine versions far better than it did last year. thanks for your patience, those who submitted weird big PNGs in. if you have any PNGs (or any other file of course) that suddenly render with the wrong colour, I'm interested to see them
- the network->downloaders menu has new 'user-run downloader repository' and 'help: random 403 errors' items. the former links to https://github.com/CuddleBear92/Hydrus-Presets-and-Scripts, the latter opens a little help window that talks about the infrastructure changes that are slowly breaking some of the original default downloaders. this help window is now linked off any downloader 'retry' icon button that has 'ignored' stuff to retry, and I replicated it in the 'getting started with downloaders' help, so I hope anyone who gets perplexed by a 403 will now see what's going on. there is no excellent solution here, but I am thinking about it (issue #1963)
fixes
- fixed the new unified directory picker to always return a path with backslashes on Windows. it was producing one with forward slashes, which in certain listdir operations (like 'add folder' in the import files dialog) was generating paths with mixed slashes and backslashes(!!). python handles this situation well and it didn't break anything, but it is ugly, unwise, and caused some path duplicates since you could add the same path to certain lists with both slashes and backslashes. the various 'add filename(s)' dialogs were already normalising correctly, so I believe we are fully covered here now. thank you to the users who reported this
- fixed a stupid bug that meant if you renamed an import folder, it would always be renamed as a non-duplicate 'import folder name (1)' alternate
- I think I have fixed the issue where the new QtMediaPlayer could sometimes 'scroll inside' the viewport of the player on a mouse wheel event. this seemed to be aggravated by the aspect ratio changes caused by having the TEST: Use the same QtMediaPlayer through media transitions checkbox on. I was going to force everyone out of this test mode (it is currently default), but I think I fixed it correct so I won't yet. let me know how things are now--if we are good, then I think it is time to formalise this test into a real thing
- fixed some bad reset code in the duplicate potential pair search when you have the 'try to state a final estimate' setting on. it was possible for it to do some confidence math on a hitrate of over 100% and it got into trouble when generating the count. the reset code is nicer and the math now checks for and handles non-sensible input (issue #1960)
client api
- fixed the 'fetch SVG file for rating service' routine when the SVG file is a user override in their db/static dir
- fixed the 'this service doesn't use an SVG rating' 404 when fetching SVG files for rating services--it was 500ing previously. added a unit test for this too
- fixed the error handling in this SVG fetch routine to handle certain other error cases better
- client api version is now 88