[client] Add light mode with system, light, and dark theme options (#7344)

* desktop UI light mode

* Theme review fixes plus macOS window outline fix

* Windows runtime chrome re-theming plus apply serialization

* Windows chrome threading and theme event ordering fixes

* Darken toggle and setting sidebar text

* resolve theme appearance, apply on UI thread

* read theme once per window

* Re-assert Windows dark opt-in after SetTheme

* split app-wide GTK theming from per-window chrome

* Update Wails dependency and checksums

* KDE tray icon panel fix

* Five review fixes: theme ordering, cgo dedup, KDE panel resolution

* Path guard hardening, toggle contrast, windows comment

* non-vacuous escape tests

* Default view edits

* Polish settings nav, controls, borders, and disc

* Profiles settings boarder, modals, and buttons

* Additional edits based on feedback

* Switch colors away from slight blue hue

* Update missing lang

* Fix vertical tab active view

client/ui/frontend/src/modules/settings/SettingsSection.tsx

@@ -16,7 +16,7 @@ export const SectionGroup = ({
         {...(disabled ? { inert: "" } : {})}
         className={cn(
             "mb-8 rounded-md px-1 outline-none last:mb-1",
-            "focus-visible:ring-2 focus-visible:ring-white/60 focus-visible:ring-offset-2 focus-visible:ring-offset-nb-gray-940",
+            "focus-visible:ring-2 focus-visible:ring-nb-gray-50/60 focus-visible:ring-offset-2 focus-visible:ring-offset-nb-gray-940",
             disabled && "pointer-events-none opacity-30",
         )}
     >
@@ -33,7 +33,7 @@ export const SettingsBottomBar = ({ children }: { children: ReactNode }) => (
         <div className={"absolute bottom-0 left-0 w-full"}>
             <div
                 className={
-                    "flex w-full justify-end gap-3 border-t border-nb-gray-920 bg-nb-gray-940 px-8 py-5"
+                    "flex w-full justify-end gap-3 border-t border-nb-gray-800 bg-nb-gray-940 px-8 py-5 dark:border-nb-gray-920"
                 }
             >
                 {children}