Manager roles: access to storage, accounting and the AI tab corrected

Technical and commercial managers can now open, upload and manage files of every category in plant and organization storage. Accounting and contracts belong to commercial managers; technical managers no longer reach them, nor the organization's AI overview and chat-history clearing, which stay with admins and moderators. Members with viewer access can no longer open plant storage files.

• Uploading no longer depends on a file's category; categories still govern who can open, change or delete it.
• The organization page shows the AI tab only to members who may actually open it.