Approval workflow for resource bookings (pending → approved/declined)

[matt-ek]

Is your feature request related to a problem? Please describe.

At the moment, every user with access to a resource can book it directly. The booking is immediately confirmed and blocks the resource calendar.

In many organizational contexts (parishes, municipalities, NGOs, schools, companies), resources cannot always be booked freely. For example:

• A parish bus should only be used if approved by a responsible person.
• A large hall may require confirmation to avoid conflicts or unauthorized usage.
• Special equipment (e.g. beamers, cameras) might only be available to certain groups, and usage must be validated first.

Currently, there is no approval process for bookings in Nextcloud Calendar Resource Management. This means organizations either:

• Have to trust that all users book responsibly (risk of misuse).
• Or rely on manual oversight (e.g. reviewing calendars and contacting people), which is inefficient.

Describe the solution you'd like

Introduce an approval workflow for resources:

• When a user creates a booking, it is stored as pending.
• Resource managers (or designated approvers) receive a notification.
• They can approve or decline the booking.
• Once approved, the resource shows up as confirmed (busy).
• Pending requests should not block the resource (or optionally block it until decision).

Additional options / refinements:

• Configurable per resource: Admins can decide if approval is required or not.
• Notifications via Talk, email, or Nextcloud notifications for quick handling.
• Optional auto-approve rules (e.g. "user X can always book without approval").
• Audit trail: who requested, who approved, when.

Describe alternatives you've considered

• Manual calendar management: A responsible person edits or deletes bookings if inappropriate → too late and frustrating for users.
• Virtual user ownership: Resource managed by a separate user account, who shares calendar selectively. However, this does not provide an approval mechanism, only access control.
• External booking systems: Provide approval, but break integration with Nextcloud Calendar and require duplication.

Additional context

• In municipal or parish settings, cars, halls, and equipment are often shared between multiple groups (youth, choir, administration). A lightweight approval workflow would prevent misuse and make responsibilities clear.
• In schools or NGOs, staff often need oversight before approving external group usage of facilities.
• Approval workflows are a standard feature in other calendar/resource booking systems (e.g. Exchange/Outlook Room Booking) and would make Nextcloud Resource Management much more competitive.

[st3iny]

Thanks for the feature request. This makes sense in my opinion.