feat(minimap): show proportional workspace overview

[Yt4aZaveta]

Changes

• Show the complete occupied workspace on the minimap: Home, windows, Browser, plugin cards, sticky notes, and regions.
• Preserve each object's proportions, relative size, and position.
• Omit session names and use the existing provider icons.
• Match the window stacking order on the Canvas.
• Update only the camera viewport during pan and zoom, avoiding workspace-layer rendering on every camera movement.