fix(web): dark-mode tokens for popup primitives + theme-color/color-scheme sync (#68)

Tooltip, toast, and combobox popups still hardcoded light colors
(bg-white, neutral-*, indigo-50) and rendered as white boxes in dark
mode; the objects-table page-size select did the same in app code.
Swap all of them to theme tokens (popover/accent/muted/destructive/
success) and replace the toast's literal "×" with the lucide X icon.

Wire browser chrome into the theme: color-scheme via CSS on
:root/.dark (follows the in-app toggle, not just the OS), a
theme-color meta kept in sync by the preload script and applyTheme(),
plus a unit test for the meta sync.

Extend check-no-raw-colors to also flag shadeless white/black
utilities outside components/ui/ so the objects-table case can't
recur.

Closes #68

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/components/ui/combobox.tsx

@@ -31,7 +31,7 @@ function ComboboxClear({ className, ...props }: ComboboxPrimitive.Clear.Props) {
     <ComboboxPrimitive.Clear
       data-slot="combobox-clear"
       className={cn(
-        "absolute right-6 text-neutral-400 hover:text-neutral-700",
+        "absolute right-6 text-muted-foreground hover:text-foreground",
         className,
       )}
       {...props}
@@ -43,7 +43,7 @@ function ComboboxTrigger({ className, ...props }: ComboboxPrimitive.Trigger.Prop
   return (
     <ComboboxPrimitive.Trigger
       data-slot="combobox-trigger"
-      className={cn("absolute right-1 text-neutral-500", className)}
+      className={cn("absolute right-1 text-muted-foreground", className)}
       {...props}
     />
   );
@@ -56,7 +56,7 @@ function ComboboxPopup({ className, ...props }: ComboboxPrimitive.Popup.Props) {
         <ComboboxPrimitive.Popup
           data-slot="combobox-popup"
           className={cn(
-            "max-h-64 min-w-48 overflow-auto rounded border bg-white p-1 text-sm shadow-md",
+            "max-h-64 min-w-48 overflow-auto rounded border bg-popover p-1 text-sm text-popover-foreground shadow-md",
             className,
           )}
           {...props}
@@ -81,7 +81,7 @@ function ComboboxItem({ className, ...props }: ComboboxPrimitive.Item.Props) {
     <ComboboxPrimitive.Item
       data-slot="combobox-item"
       className={cn(
-        "flex cursor-default items-center gap-2 rounded px-2 py-1 data-[highlighted]:bg-indigo-50",
+        "flex cursor-default items-center gap-2 rounded px-2 py-1 data-[highlighted]:bg-accent data-[highlighted]:text-accent-foreground",
         className,
       )}
       {...props}
@@ -103,7 +103,7 @@ function ComboboxEmpty({ className, ...props }: ComboboxPrimitive.Empty.Props) {
   return (
     <ComboboxPrimitive.Empty
       data-slot="combobox-empty"
-      className={cn("px-2 py-1 text-neutral-500", className)}
+      className={cn("px-2 py-1 text-muted-foreground", className)}
       {...props}
     />
   );

web/src/components/ui/toast.tsx

@@ -1,6 +1,7 @@
 import type * as React from "react";
 import { useTranslation } from "react-i18next";
 import { Toast as ToastPrimitive } from "@base-ui/react/toast";
+import { X } from "lucide-react";
 
 import { cn } from "@/lib/utils";
 import { toastManager } from "@/toast/toast-manager";
@@ -14,9 +15,9 @@ function ToastList() {
       toast={toast}
       data-slot="toast"
       className={cn(
-        "flex items-start gap-2 rounded-md border bg-white p-3 text-sm shadow-md",
-        toast.type === "error" && "border-red-300",
-        toast.type === "success" && "border-green-300",
+        "flex items-start gap-2 rounded-md border bg-popover p-3 text-sm text-popover-foreground shadow-md",
+        toast.type === "error" && "border-destructive",
+        toast.type === "success" && "border-success",
       )}
     >
       <div className="flex-1">
@@ -28,15 +29,15 @@ function ToastList() {
         )}
         <ToastPrimitive.Description
           data-slot="toast-description"
-          className="text-neutral-700"
+          className="text-muted-foreground"
         />
       </div>
       <ToastPrimitive.Close
         data-slot="toast-close"
         aria-label={t("common.close")}
-        className="text-neutral-400 hover:text-neutral-700"
+        className="text-muted-foreground hover:text-foreground"
       >
-        ×
+        <X className="size-4" aria-hidden="true" />
       </ToastPrimitive.Close>
     </ToastPrimitive.Root>
   ));

web/src/components/ui/tooltip.tsx

@@ -22,7 +22,7 @@ function TooltipPopup({ className, ...props }: TooltipPrimitive.Popup.Props) {
     <TooltipPrimitive.Popup
       data-slot="tooltip-popup"
       className={cn(
-        "rounded border bg-white px-2 py-1 text-sm shadow-md",
+        "rounded border bg-popover px-2 py-1 text-sm text-popover-foreground shadow-md",
         className,
       )}
       {...props}