Revoke Share Link

Revoke the active share link for a project.

Permanently invalidates the current share token. Re-enabling sharing will generate a new token (old links stay dead). Requires write access to the project.

Args: project_id: UUID of the project (validated for write access) share_service: ProjectShareService for share link operations

Returns: Success confirmation

Raises: HTTPException: 404 if no active share link exists