feat(ui): give every panel one scrollbar, select and slider skin

Every scrolling surface carries the kit's .ui-scroll, which
draws the thin themed scrollbar from --scroll-thumb and --scroll-track; the
Context panel and others drew the platform's light scrollbar because the
page declares no dark color-scheme. The per-panel scrollbar rules go; Cyber
sets the two tokens and Cockpit's HUD windows keep their accent tint.

Selects draw .gev-field's own chevron instead of the platform arrow, the
voice selects join .gev-field, number fields keep dark spinners, and the
Street Level range uses the shared slider in its green.

src/ui/styles/cyber.css

@@ -41,8 +41,6 @@
   min-height: 0;
   overflow-y: auto;
   overscroll-behavior: contain;
-  scrollbar-width: thin;
-  scrollbar-color: rgba(165, 188, 199, 0.35) transparent;
 }
 
 :root[data-ui-theme='cyber'] .cctv-panel-inner > .cyber-panel-body {
@@ -68,8 +66,6 @@
   min-height: 0;
   overflow-y: auto;
   overscroll-behavior: contain;
-  scrollbar-width: thin;
-  scrollbar-color: rgba(165, 188, 199, 0.35) transparent;
 }
 
 :root[data-ui-theme='cyber'] #pp-toggles > .pp-panel-body > * {
@@ -82,6 +78,8 @@
 
 :root[data-ui-theme='cyber'] {
   color-scheme: dark;
+  --scroll-thumb: rgba(165, 188, 199, 0.35);
+  --scroll-track: transparent;
   --cyber-red: #c45454;
   --cyber-red-bright: #e16666;
   --cyber-slate: #26343a;
@@ -796,6 +794,12 @@
   accent-color: var(--cyber-red);
 }
 
+/* Street Level's range wears Cyber's slider accent like every other range. */
+:root[data-ui-theme='cyber'] .sl-range {
+  --accent: inherit;
+  --accent-glow: inherit;
+}
+
 :root[data-ui-theme='cyber']
   :where(button, a[href], input, select, textarea):focus-visible {
   outline-color: var(--cyber-red-bright) !important;