feat: workspace inline panel and layout

[HelderMendes]

Workspace feature: a persistent inline panel that lets users manage their active workspace while browsing the platform.

New components

• WorkspaceInlinePanel — sticky panel displaying workspace status and quick actions
• WorkspacePanel — detailed view for managing workspace contents
• WorkspaceSetter — helper component to programmatically set the workspace context
• WorkspaceContentWrapper — handles state and visibility logic for workspace-enabled pages

Layout update

• main-content.tsx — ensure correct spacing across page layouts