fix(dashboard): restore readable text and switch contrast in fullscreen console (#10135)

The fullscreen view of ConsoleDisplayer kept Vuetify's default
`--v-theme-on-surface` and `--v-theme-surface-variant`, which on the
forced `#1e1e1e` background rendered body text nearly invisible and
left `.v-switch__track` blending into the chrome.

- Force `--v-theme-on-surface` to white and set `color: #fff` for
  `#console-wrapper:fullscreen` so log output and controls stay
  legible.
- Override `--v-theme-surface-variant` on the fullscreen switch track
  so the toggle knob reads against the dark wrapper.

dashboard/src/components/shared/ConsoleDisplayer.vue

@@ -408,10 +408,16 @@ export default {
 }
 
 #console-wrapper:fullscreen {
+  --v-theme-on-surface: 255, 255, 255;
   background-color: #1e1e1e;
+  color: #fff;
   padding: 20px;
 }
 
+#console-wrapper:fullscreen :deep(.v-switch__track) {
+  --v-theme-surface-variant: 163, 163, 163;
+}
+
 .filter-controls {
   display: flex;
   align-items: center;