[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/layouts/AppRightPanel.tsx

@@ -19,7 +19,7 @@ export const AppRightPanel = ({ children, overlay, overlayOpen = false, classNam
         <div
             className={cn(
                 "wails-no-draggable relative m-5",
-                "border border-nb-gray-920 bg-nb-gray-940",
+                "border border-nb-gray-800 bg-nb-gray-940 dark:border-nb-gray-920",
                 "flex min-h-0 min-w-0 flex-1 flex-col overflow-hidden rounded-xl rounded-br-2xl",
                 className,
             )}