feat(ui): refine gem-blue acrylic palette and focus borders

Derive the gem-blue palette with OKLCH tonal and complementary-color
rules while preserving acrylic opacity, blur and surface hierarchy.

Darker focus tokens exposed stacked field rings, fallback outlines and
persistent basemap selection rings. Keep fallback focus styles in the
base layer and use one themed field boundary or inset card stroke.
Preserve keyboard focus, invalid states and native input semantics.

Add browser regression coverage for pointer and keyboard focus, all
basemap presentations, narrow layouts and rendered contrast.

Validation in an isolated checkout: pnpm lint, pnpm typecheck,
pnpm test (393 tests), focused browser suites and pnpm build.

src/features/map/core/components/map-control-styles.ts

@@ -10,6 +10,9 @@ export const MAP_COMPACT_RADIUS_CLASS_NAME = MAP_CONTROL_RADIUS_CLASS_NAME;
 
 export const MAP_ICON_CELL_RADIUS_CLASS_NAME = "rounded-lg";
 
+export const MAP_SELECTION_CARD_FOCUS_CLASS_NAME =
+  "outline-hidden focus-visible:outline-1 focus-visible:outline-solid focus-visible:outline-[var(--action-focus-ring)] focus-visible:-outline-offset-1";
+
 export const MAP_CONTROL_SURFACE_CLASS_NAME =
   "acrylic-control border";