feat(29-02): update ComparisonTable, CatalogSearchOverlay, ImageUpload

Replace object-cover with GearImage across ComparisonTable,
CatalogSearchOverlay (2 instances), and ImageUpload preview.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/client/components/ImageUpload.tsx

@@ -1,9 +1,11 @@
 import { useRef, useState } from "react";
 import { apiUpload } from "../lib/api";
+import { GearImage, imageContainerBg } from "./GearImage";
 
 interface ImageUploadProps {
 	value: string | null;
 	imageUrl?: string | null;
+	dominantColor?: string | null;
 	onChange: (filename: string | null) => void;
 }
 
@@ -13,6 +15,7 @@ const ACCEPTED_TYPES = ["image/jpeg", "image/png", "image/webp"];
 export function ImageUpload({
 	value: _value,
 	imageUrl,
+	dominantColor,
 	onChange,
 }: ImageUploadProps) {
 	const [uploading, setUploading] = useState(false);
@@ -70,13 +73,18 @@ export function ImageUpload({
 			<div
 				onClick={() => inputRef.current?.click()}
 				className="relative w-full aspect-[4/3] rounded-xl overflow-hidden cursor-pointer group"
+				style={{
+					backgroundColor: displayUrl
+						? imageContainerBg(dominantColor)
+						: undefined,
+				}}
 			>
 				{displayUrl ? (
 					<>
-						<img
+						<GearImage
 							src={displayUrl}
 							alt="Item"
-							className="w-full h-full object-cover"
+							dominantColor={dominantColor}
 						/>
 						{/* Remove button */}
 						<button