Brand logos now display with correct aspect ratio

Wide wordmarks in sidebar and settings tables now render with object-contain instead of being cropped to a square.

Bug Fixes

Organization and branch logos throughout the app were being rendered via the square-aspect <Avatar> component, which clipped wide wordmarks to a sliver. We've introduced <BrandMark> — a new component that renders logos inside a bounded square with object-contain, preserving their aspect ratio.

You'll see the fix in the workspace switcher (collapsed and expanded), the organization and branch lists inside the dropdown, and the branches settings table. User profile photos still use the round/square <Avatar> treatment as before.