Removed the stray blue selection outline around selected cards. It was React Flow's
stock rgba(0, 89, 220, …) selection styling (.react-flow__nodesselection-rect /
.react-flow__selection) leaking through the imported base CSS — now neutralised in
globals.css so it no longer clashes with the ink design system.
Removed the blue vertical bars on the left/right of resizable cards. These were the
React Flow resize-control "line" variant, whose edge line defaults to #3367d9. Forced
--xy-resize-background-color: transparent so only our own accent resize guides show.
