feat: allow users to get notified about changes in a collective

[mejo-]

Sends notifications if pages got updated or deleted. Doesn't send notifications when a page got created on purpose as usually pages get renamed straight after they got created.

Also allows to turn notifications off completely for a collective, which also silences notifications on being mentioned in a page.

Fixes: #317

🖼️ Screenshots

Collectives Action Menu 1	Collectives Action Menu 2

Notification

🚧 TODO

So far it only sends notifications on page updates (content updated, page renamed/moved/deleted, emoji changed). I wonder whether adding/removing members shall trigger a notification as well. And how about tagging/untagging pages etc.?

Also, so far there's only three states: "all changes", "@-mention only" (the default) and "off" (no notifications at all). I wonder whether we want to make this more fine-grained, but maybe that's something for a follow-up later on.

• Decide if collective actions is the right place for the subscribe toggle in UI
• Playwright tests
• Consider activity app integration

🏁 Checklist

• Code is properly formatted (npm run lint / npm run stylelint / composer run cs:check)
• Sign-off message is added to all commits
• Tests (unit, integration and/or end-to-end) passing and the changes are covered with tests

🤖 AI (if applicable)

• The content of this PR was partly generated using AI tools
• The AI-generated content was reviewed, comprehended and tested by my

[marcoambrosini]

Hi Jonas, I think that the location you've chosen makes sense, I would maybe do it like in Talk though, using a sub-action-menu, so we have more space to be clear with labels and icons.

Screen.Recording.2026-05-29.at.16.51.45.mov

On top of that, this could be indeed put in the collective settings dialog. Just like in Talk, the dialog could be exposed to all users, and have the conditional display logic (owner/user) on settings section instead. Templates could also go in here.

[mejo-]

Hi Jonas, I think that the location you've chosen makes sense, I would maybe do it like in Talk though, using a sub-action-menu, so we have more space to be clear with labels and icons.

Great idea @marcoambrosini. Implemented now, see the updated screenshots.

[marcoambrosini]

🥳 really nice!

[blizzz]

I wonder whether adding/removing members shall trigger a notification as well. And how about tagging/untagging pages etc.?
Also, so far there's only three states: "all changes", "@-mention only" (the default) and "off" (no notifications at all). I wonder whether we want to make this more fine-grained, but maybe that's something for a follow-up later on.

That might be worthy activity information, but I am doubtful whether they are worth to create a notification. I would keep it as is for now. (Tagging might probably also need to discriminate between tag types and user privileges if it was implemented 🤔)