feat(11-02): add view toggle, Reorder.Group drag-to-reorder, and rank badges in grid view

- Thread detail page: list/grid view toggle with LayoutList/LayoutGrid icons
- List view (active threads): Reorder.Group with CandidateListItem for drag-to-reorder
- List view (resolved threads): static CandidateListItem with rank badges, no drag handles
- Grid view: CandidateCard components with rank badges (gold/silver/bronze)
- tempItems pattern prevents React Query flicker during drag
- handleDragEnd fires PATCH /candidates/reorder after drag completes
- View toggle defaults to list view via uiStore candidateViewMode

src/client/components/CandidateCard.tsx

@@ -3,6 +3,7 @@ import { useWeightUnit } from "../hooks/useWeightUnit";
 import { formatPrice, formatWeight } from "../lib/formatters";
 import { LucideIcon } from "../lib/iconData";
 import { useUIStore } from "../stores/uiStore";
+import { RankBadge } from "./CandidateListItem";
 import { StatusBadge } from "./StatusBadge";
 
 interface CandidateCardProps {
@@ -20,6 +21,7 @@ interface CandidateCardProps {
 	onStatusChange: (status: "researching" | "ordered" | "arrived") => void;
 	pros?: string | null;
 	cons?: string | null;
+	rank?: number;
 }
 
 export function CandidateCard({
@@ -37,6 +39,7 @@ export function CandidateCard({
 	onStatusChange,
 	pros,
 	cons,
+	rank,
 }: CandidateCardProps) {
 	const unit = useWeightUnit();
 	const currency = useCurrency();
@@ -159,6 +162,7 @@ export function CandidateCard({
 					{name}
 				</h3>
 				<div className="flex flex-wrap gap-1.5">
+					{rank != null && <RankBadge rank={rank} />}
 					{weightGrams != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-400">
 							{formatWeight(weightGrams, unit)}

src/client/routes/threads/$threadId.tsx

@@ -1,6 +1,12 @@
 import { createFileRoute, Link } from "@tanstack/react-router";
+import { Reorder } from "framer-motion";
+import { useEffect, useState } from "react";
 import { CandidateCard } from "../../components/CandidateCard";
-import { useUpdateCandidate } from "../../hooks/useCandidates";
+import { CandidateListItem } from "../../components/CandidateListItem";
+import {
+	useReorderCandidates,
+	useUpdateCandidate,
+} from "../../hooks/useCandidates";
 import { useThread } from "../../hooks/useThreads";
 import { LucideIcon } from "../../lib/iconData";
 import { useUIStore } from "../../stores/uiStore";
@@ -14,7 +20,21 @@ function ThreadDetailPage() {
 	const threadId = Number(threadIdParam);
 	const { data: thread, isLoading, isError } = useThread(threadId);
 	const openCandidateAddPanel = useUIStore((s) => s.openCandidateAddPanel);
+	const candidateViewMode = useUIStore((s) => s.candidateViewMode);
+	const setCandidateViewMode = useUIStore((s) => s.setCandidateViewMode);
 	const updateCandidate = useUpdateCandidate(threadId);
+	const reorderMutation = useReorderCandidates(threadId);
+
+	const [tempItems, setTempItems] =
+		useState<typeof thread extends { candidates: infer C } ? C : never | null>(
+			null,
+		);
+
+	// Clear tempItems when server data changes (biome-ignore: thread?.candidates is intentional dep)
+	// biome-ignore lint/correctness/useExhaustiveDependencies: thread?.candidates is the intended trigger
+	useEffect(() => {
+		setTempItems(null);
+	}, [thread?.candidates]);
 
 	if (isLoading) {
 		return (
@@ -53,6 +73,16 @@ function ThreadDetailPage() {
 		? thread.candidates.find((c) => c.id === thread.resolvedCandidateId)
 		: null;
 
+	const displayItems = tempItems ?? thread.candidates;
+
+	function handleDragEnd() {
+		if (!tempItems) return;
+		reorderMutation.mutate(
+			{ orderedIds: tempItems.map((c) => c.id) },
+			{ onSettled: () => setTempItems(null) },
+		);
+	}
+
 	return (
 		<div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-6">
 			{/* Header */}
@@ -88,9 +118,9 @@ function ThreadDetailPage() {
 				</div>
 			)}
 
-			{/* Add candidate button */}
-			{isActive && (
-				<div className="mb-6">
+			{/* Toolbar: Add candidate + view toggle */}
+			<div className="mb-6 flex items-center gap-3">
+				{isActive && (
 					<button
 						type="button"
 						onClick={openCandidateAddPanel}
@@ -111,10 +141,38 @@ function ThreadDetailPage() {
 						</svg>
 						Add Candidate
 					</button>
-				</div>
-			)}
+				)}
+				{thread.candidates.length > 0 && (
+					<div className="flex items-center gap-1 bg-gray-100 rounded-lg p-0.5">
+						<button
+							type="button"
+							onClick={() => setCandidateViewMode("list")}
+							className={`p-1.5 rounded-md transition-colors ${
+								candidateViewMode === "list"
+									? "bg-gray-200 text-gray-900"
+									: "text-gray-400 hover:text-gray-600"
+							}`}
+							title="List view"
+						>
+							<LucideIcon name="layout-list" size={16} />
+						</button>
+						<button
+							type="button"
+							onClick={() => setCandidateViewMode("grid")}
+							className={`p-1.5 rounded-md transition-colors ${
+								candidateViewMode === "grid"
+									? "bg-gray-200 text-gray-900"
+									: "text-gray-400 hover:text-gray-600"
+							}`}
+							title="Grid view"
+						>
+							<LucideIcon name="layout-grid" size={16} />
+						</button>
+					</div>
+				)}
+			</div>
 
-			{/* Candidate grid */}
+			{/* Candidates */}
 			{thread.candidates.length === 0 ? (
 				<div className="py-12 text-center">
 					<div className="mb-3">
@@ -131,9 +189,50 @@ function ThreadDetailPage() {
 						Add your first candidate to start comparing.
 					</p>
 				</div>
+			) : candidateViewMode === "list" ? (
+				isActive ? (
+					<Reorder.Group
+						axis="y"
+						values={displayItems}
+						onReorder={setTempItems}
+						className="flex flex-col gap-2"
+					>
+						{displayItems.map((candidate, index) => (
+							<CandidateListItem
+								key={candidate.id}
+								candidate={candidate}
+								rank={index + 1}
+								isActive={isActive}
+								onStatusChange={(newStatus) =>
+									updateCandidate.mutate({
+										candidateId: candidate.id,
+										status: newStatus,
+									})
+								}
+							/>
+						))}
+					</Reorder.Group>
+				) : (
+					<div className="flex flex-col gap-2" onPointerUp={handleDragEnd}>
+						{displayItems.map((candidate, index) => (
+							<CandidateListItem
+								key={candidate.id}
+								candidate={candidate}
+								rank={index + 1}
+								isActive={isActive}
+								onStatusChange={(newStatus) =>
+									updateCandidate.mutate({
+										candidateId: candidate.id,
+										status: newStatus,
+									})
+								}
+							/>
+						))}
+					</div>
+				)
 			) : (
 				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-					{thread.candidates.map((candidate) => (
+					{thread.candidates.map((candidate, index) => (
 						<CandidateCard
 							key={candidate.id}
 							id={candidate.id}
@@ -155,6 +254,7 @@ function ThreadDetailPage() {
 							}
 							pros={candidate.pros}
 							cons={candidate.cons}
+							rank={index + 1}
 						/>
 					))}
 				</div>