fix(admin-settings): space list and sidebar issues

[JammingBen]

• Adds missing space manager names in sidebar. We need to load the manager names via the permissions because we don't have the shares loaded in the admin settings.
• Fixes the broken space list after creating a space due to the missing permissions. Note that we currently can't fetch the permissions after creating a space because the server doesn't support expand on a drive GET request. Hence we fall back to a member count of 1 (always accurate directly after creating) and an empty list of manager names.
• plus a few small improvements and script setup refactor. Best reviewed via commits.

fixes #1178
fixes #1251

[Copilot]

Pull Request Overview

This PR fixes missing space manager names in the sidebar for admin settings by adding a fallback mechanism when space member shares are not loaded.

• Adds fallback logic to retrieve manager information from space permissions when member shares are unavailable
• Imports CollaboratorShare type to support the permission-based manager detection
• Updates the ownerUsernames computed property to handle both shared members and permission-based scenarios

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