Lane selection sheds its slab — a hairline edge with a soft halo, intensity inverse to area

The whole-lane wash-and-solid-ring scaled its emphasis with the lane's
area: what read as a ring on a card read as a slab on a column. Resettled
as the system focus ring's vocabulary at selection strength — a hairline
accent edge with a soft accent glow bleeding outward, riding the stroke
shape rather than the translucent plate (a shadow behind it would bleed
through as murk), and no wash at all: nothing tints the cards' backdrop,
and lane colour stays the accent band's alone. Under Increase Contrast the
halo yields to the solid full-alpha ring — "strengthens borders" means
crisper, and a blur is the one thing a border cannot become — so the
setting sees exactly the indicator it always has; cards and trash rows are
card-scale and keep the solid ring at every contrast. One selection
vocabulary, pinned by Accommodations.drawsSelectionHalo and its test.

Claude-Session: https://claude.ai/code/session_014PtZdPwqZuqEDLc6wZMtEy

Kanban/UI/Accommodations.swift

@@ -75,6 +75,20 @@ enum Accommodations {
         contrast == .increased ? 1 : base
     }
 
+    /// Whether a selected lane draws its **halo** — the soft accent glow bleeding outward from the
+    /// plate's hairline edge (`LaneView.selectionStroke`), the system focus ring's vocabulary at
+    /// selection strength.
+    ///
+    /// Under Increase Contrast the answer is no, and that is the setting's own logic rather than a
+    /// retreat: "strengthens borders and the selection indicator" means *crisper*, and a blur is
+    /// the one thing a border cannot become. The edge instead goes full-alpha and heavier
+    /// (`accentOpacity`, `borderWidth` at the solid ring's base), so the setting sees the same
+    /// unambiguous solid ring it always has — the halo is the resting treatment's softness, not
+    /// the indicator itself.
+    static func drawsSelectionHalo(contrast: ColorSchemeContrast) -> Bool {
+        contrast != .increased
+    }
+
     /// Increase Contrast, asked of AppKit rather than of the SwiftUI environment — for callers built
     /// outside a rendered hierarchy, where the environment's accessibility values are not reliably
     /// populated (`Motion.prefersReducedMotion`'s constituency).