gildas-lormeau/SingleFile v1.34.0 on GitHub

The options page displays a warning when the extension is not allowed to access local files, with the steps to allow it: "Access local files on your computer" in the permissions of the extension since Firefox 153, where it is off by default, and "Allow access to file URLs" in Chromium-based browsers. Without it, the infobar is not displayed on saved pages and pages opened from the filesystem cannot be saved. The help page and the FAQ describe it too (#2014)
New hidden option embeddedScript (core 1.9.0), set from the options editor: JavaScript code inserted at the end of the saved page, kept even though the scripts of the page are removed. Combined with a custom stylesheet that keeps hidden elements, it lets a user restore the tabs of a saved page, for example
Help page: the examples of the time template variables use ":" instead of "_" (#2041 by @lstngr), and the ISO variables are documented as UTC (#2042)
Translations: Russian reviewed (#2039 by @solokot), Swedish reviewed (#2040 by @NickWick13), German label of the proof of existence option fixed, missing translations and spelling mistakes fixed in several locales

Filename templates (core 1.8.1): the spaces written in the template are kept instead of being collapsed into a single space; tabs, line breaks and other whitespace characters are still replaced with spaces, one for one (#2042)
Filename templates (core 1.8.1): a substitution rule that removes characters, and the "replace emojis with text" option, no longer leave two spaces around the removed character or a space before the file extension
Filename templates (core 1.8.1): a folder name ending with a dot no longer loses its separator ("docs./file" was saved as "docs._file"), a ".." segment is removed as a whole segment instead of wherever "../" appears ("Loading.../page" was saved as "Loading.page"), and trailing dots and spaces are removed from every folder name; the filename preview on the options page follows the same rules
A missing image is no longer requested a second time when its currentSrc is the same URL as its src, which doubled the network wait on slow or unavailable images (gildas-lormeau/single-file-core#11 by @pirate)