File Integration Into Workspace

Point the organization's provider integration at this workspace.

Everything a provider sync creates from here on files into this workspace instead of the organization default, so a team's newly synced agents land in the team's workspace.

Existing agents are NOT relocated: an agent already synced keeps the workspace it is in, which is the same rule sync_workspace_id follows when it re-syncs one. Resources are only ever created into a workspace, never moved between them.

Org admin only. Passing the default workspace restores the previous behaviour.