Add Team Activity resource provider and TeamFolder root fi…

[hefftich]

…le id

• Resolves:
  Show activity of team in Teams app circles#2692

• Relates;

nextcloud/circles#3030
nextcloud/activity#3024
nextcloud/deck#8516

Summary

Introduce ITeamActivityResourceProvider as an optional capability for ITeamResourceProvider implementations to resolve Team resources into Activity scopes, backed by the new TeamActivityScope value object.

The Activity app can use these scopes to include activity from Team-linked resources while each provider resolves only objects visible to the requesting user. Providers that do not support Activity require no changes.

Expose the filecache root ID on TeamFolder so filesystem-backed providers can resolve the contents of Team folders into Activity scopes.

Consumers

The initial consumers are:

• Activity: resolves Team-linked resources into Activity object scopes.
• Group folders: exposes Team folder roots as file Activity scopes.
• Deck: exposes Team-linked boards as Deck Activity scopes.

TODO

• ...

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

claude-sonnet-4.5