Port browser extension to manifest v3

[snarfed]

The Chrome Web Store is transitioning from manifest v2, which the Bridgy browser extension is currently on, to manifest v3. Their timeline says they'll stop accepting new extensions with v2 in Jan 2022, and Chrome itself will stop running v2 extensions in Jan 2023. Guess we'll have to migrate.

...except Firefox evidently doesn't support v3 yet?! Um, ...?

[snarfed]

Evidently manifest v3 has been a bunch of drama between the different browser vendors. TLDR: Chrome and Edge are diverging significantly from Firefox in MV3 so far in their supported APIs, and the situation is still in flux, but Chrome is turning off MV2 support in Jan 2023.

Sadly, two of the biggest sources of controversy, WebRequest and background pages, are key APIs that our browser extension depends on. Chrome is replacing them with declarativeNetRequest and Service Workers (migration guide), respectively. Firefox's declarativeNetRequest support is evidently currently in "Developer Preview," and they say they'll ship Service Worker support, but haven't yet.

Here's Firefox's MV3 migration guide.

[snarfed]

cc @tantek. Standards drama! 😢🍿:hugstandards: (or whatever the hugops equivalent is)

[snarfed]

Oops, attached the wrong commit ^, that one's unrelated.

[snarfed]

https://discourse.mozilla.org/tag/manifest-v3

[snarfed]

https://blog.mozilla.org/addons/2022/06/08/manifest-v3-firefox-developer-preview-how-to-get-involved/

[snarfed]

https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Background_scripts#convert_to_non-persistent

[snarfed]

Asked about declarativeNetRequest support in Firefox.

[snarfed]

d85f7ac, 755bf41

[snarfed]

Status: Chrome is now migrated to manifest v3, Firefox is still on v2. Same codebase, different manifest files.

[snarfed]

Closing as obsolete; Bridgy's browser extension is deprecated.