feat(35-02): add image skeleton loading states to all card types

- Add useState(false) loaded state to ItemCard, CandidateCard, GlobalItemCard
- Show bg-gray-100 animate-pulse skeleton overlay while image loads
- Fade in image via transition-opacity duration-200 on onLoad callback
- No-image placeholders (icon on bg-gray-50) unchanged
- Add import { useState } from react to all three files with correct Biome import order

src/client/components/CandidateCard.tsx

@@ -1,4 +1,5 @@
 import { useNavigate } from "@tanstack/react-router";
+import { useState } from "react";
 import { useTranslation } from "react-i18next";
 import { useFormatters } from "../hooks/useFormatters";
 import type { CandidateDelta } from "../hooks/useImpactDeltas";
@@ -56,6 +57,7 @@ export function CandidateCard({
 	rank,
 	delta,
 }: CandidateCardProps) {
+	const [loaded, setLoaded] = useState(false);
 	const { t } = useTranslation("threads");
 	const { weight, price } = useFormatters();
 	const navigate = useNavigate();
@@ -169,14 +171,21 @@ export function CandidateCard({
 				}}
 			>
 				{imageUrl ? (
-					<GearImage
-						src={imageUrl}
-						alt={name}
-						dominantColor={dominantColor}
-						cropZoom={cropZoom}
-						cropX={cropX}
-						cropY={cropY}
-					/>
+					<div className="relative w-full h-full">
+						{!loaded && (
+							<div className="absolute inset-0 bg-gray-100 animate-pulse" />
+						)}
+						<GearImage
+							src={imageUrl}
+							alt={name}
+							dominantColor={dominantColor}
+							cropZoom={cropZoom}
+							cropX={cropX}
+							cropY={cropY}
+							onLoad={() => setLoaded(true)}
+							className={`transition-opacity duration-200 ${loaded ? "opacity-100" : "opacity-0"}`}
+						/>
+					</div>
 				) : (
 					<div className="w-full h-full bg-gray-50 flex flex-col items-center justify-center">
 						<LucideIcon

src/client/components/GlobalItemCard.tsx

@@ -1,4 +1,5 @@
 import { Link } from "@tanstack/react-router";
+import { useState } from "react";
 import { useFormatters } from "../hooks/useFormatters";
 import { GearImage, imageContainerBg } from "./GearImage";
 
@@ -29,6 +30,7 @@ export function GlobalItemCard({
 	cropX,
 	cropY,
 }: GlobalItemCardProps) {
+	const [loaded, setLoaded] = useState(false);
 	const { weight, price } = useFormatters();
 
 	return (
@@ -46,14 +48,21 @@ export function GlobalItemCard({
 				}}
 			>
 				{imageUrl ? (
-					<GearImage
-						src={imageUrl}
-						alt={`${brand} ${model}`}
-						dominantColor={dominantColor}
-						cropZoom={cropZoom}
-						cropX={cropX}
-						cropY={cropY}
-					/>
+					<div className="relative w-full h-full">
+						{!loaded && (
+							<div className="absolute inset-0 bg-gray-100 animate-pulse" />
+						)}
+						<GearImage
+							src={imageUrl}
+							alt={`${brand} ${model}`}
+							dominantColor={dominantColor}
+							cropZoom={cropZoom}
+							cropX={cropX}
+							cropY={cropY}
+							onLoad={() => setLoaded(true)}
+							className={`transition-opacity duration-200 ${loaded ? "opacity-100" : "opacity-0"}`}
+						/>
+					</div>
 				) : (
 					<div className="w-full h-full bg-gray-50 flex flex-col items-center justify-center">
 						<svg

src/client/components/ItemCard.tsx

@@ -1,4 +1,5 @@
 import { useNavigate } from "@tanstack/react-router";
+import { useState } from "react";
 import { useTranslation } from "react-i18next";
 import { useFormatters } from "../hooks/useFormatters";
 import { useDuplicateItem } from "../hooks/useItems";
@@ -52,6 +53,7 @@ export function ItemCard({
 	linkTo,
 	priceCurrency,
 }: ItemCardProps) {
+	const [loaded, setLoaded] = useState(false);
 	const { t } = useTranslation("collection");
 	const { weight, price } = useFormatters();
 	const navigate = useNavigate();
@@ -194,14 +196,21 @@ export function ItemCard({
 				}}
 			>
 				{imageUrl ? (
-					<GearImage
-						src={imageUrl}
-						alt={name}
-						dominantColor={dominantColor}
-						cropZoom={cropZoom}
-						cropX={cropX}
-						cropY={cropY}
-					/>
+					<div className="relative w-full h-full">
+						{!loaded && (
+							<div className="absolute inset-0 bg-gray-100 animate-pulse" />
+						)}
+						<GearImage
+							src={imageUrl}
+							alt={name}
+							dominantColor={dominantColor}
+							cropZoom={cropZoom}
+							cropX={cropX}
+							cropY={cropY}
+							onLoad={() => setLoaded(true)}
+							className={`transition-opacity duration-200 ${loaded ? "opacity-100" : "opacity-0"}`}
+						/>
+					</div>
 				) : (
 					<div className="w-full h-full bg-gray-50 flex flex-col items-center justify-center">
 						<LucideIcon