feat(04-02): overhaul PlanningView with empty state, pill tabs, and category filter

- Replace inline thread creation form with modal trigger
- Add educational empty state with 3-step workflow guide
- Add Active/Resolved pill tab selector replacing checkbox
- Add category filter dropdown for thread list
- Display category emoji + name badge on ThreadCard
- Add aria-hidden to decorative SVG icons for a11y
- Auto-format pre-existing indentation issues (spaces to tabs)

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

src/client/components/ThreadCard.tsx

@@ -9,6 +9,8 @@ interface ThreadCardProps {
 	maxPriceCents: number | null;
 	createdAt: string;
 	status: "active" | "resolved";
+	categoryName: string;
+	categoryEmoji: string;
 }
 
 function formatDate(iso: string): string {
@@ -33,6 +35,8 @@ export function ThreadCard({
 	maxPriceCents,
 	createdAt,
 	status,
+	categoryName,
+	categoryEmoji,
 }: ThreadCardProps) {
 	const navigate = useNavigate();
 
@@ -43,16 +47,17 @@ export function ThreadCard({
 		<button
 			type="button"
 			onClick={() =>
-        navigate({ to: "/threads/$threadId", params: { threadId: String(id) } })
+				navigate({
+					to: "/threads/$threadId",
+					params: { threadId: String(id) },
+				})
 			}
 			className={`w-full text-left bg-white rounded-xl border border-gray-100 hover:border-gray-200 hover:shadow-sm transition-all p-4 ${
 				isResolved ? "opacity-60" : ""
 			}`}
 		>
 			<div className="flex items-start justify-between mb-2">
-        <h3 className="text-sm font-semibold text-gray-900 truncate">
-          {name}
-        </h3>
+				<h3 className="text-sm font-semibold text-gray-900 truncate">{name}</h3>
 				{isResolved && (
 					<span className="ml-2 inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-gray-100 text-gray-500 shrink-0">
 						Resolved
@@ -60,6 +65,9 @@ export function ThreadCard({
 				)}
 			</div>
 			<div className="flex flex-wrap gap-1.5">
+				<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-700">
+					{categoryEmoji} {categoryName}
+				</span>
 				<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-purple-50 text-purple-700">
 					{candidateCount} {candidateCount === 1 ? "candidate" : "candidates"}
 				</span>

src/client/routes/collection/index.tsx

@@ -1,13 +1,15 @@
-import { useState } from "react";
 import { createFileRoute, useNavigate } from "@tanstack/react-router";
+import { useState } from "react";
 import { z } from "zod";
-import { useItems } from "../../hooks/useItems";
-import { useTotals } from "../../hooks/useTotals";
-import { useThreads, useCreateThread } from "../../hooks/useThreads";
 import { CategoryHeader } from "../../components/CategoryHeader";
+import { CreateThreadModal } from "../../components/CreateThreadModal";
 import { ItemCard } from "../../components/ItemCard";
-import { ThreadTabs } from "../../components/ThreadTabs";
 import { ThreadCard } from "../../components/ThreadCard";
+import { ThreadTabs } from "../../components/ThreadTabs";
+import { useCategories } from "../../hooks/useCategories";
+import { useItems } from "../../hooks/useItems";
+import { useThreads } from "../../hooks/useThreads";
+import { useTotals } from "../../hooks/useTotals";
 import { useUIStore } from "../../stores/uiStore";
 
 const searchSchema = z.object({
@@ -73,6 +75,7 @@ function CollectionView() {
 						className="inline-flex items-center gap-2 px-5 py-2.5 bg-blue-600 hover:bg-blue-700 text-white text-sm font-medium rounded-lg transition-colors"
 					>
 						<svg
+							aria-hidden="true"
 							className="w-4 h-4"
 							fill="none"
 							stroke="currentColor"
@@ -129,7 +132,10 @@ function CollectionView() {
 	return (
 		<>
 			{Array.from(groupedItems.entries()).map(
-        ([categoryId, { items: categoryItems, categoryName, categoryEmoji }]) => {
+				([
+					categoryId,
+					{ items: categoryItems, categoryName, categoryEmoji },
+				]) => {
 					const catTotals = categoryTotalsMap.get(categoryId);
 					return (
 						<div key={categoryId} className="mb-8">
@@ -164,20 +170,12 @@ function CollectionView() {
 }
 
 function PlanningView() {
-  const [showResolved, setShowResolved] = useState(false);
-  const [newThreadName, setNewThreadName] = useState("");
-  const { data: threads, isLoading } = useThreads(showResolved);
-  const createThread = useCreateThread();
+	const [activeTab, setActiveTab] = useState<"active" | "resolved">("active");
+	const [categoryFilter, setCategoryFilter] = useState<number | null>(null);
 
-  function handleCreateThread(e: React.FormEvent) {
-    e.preventDefault();
-    const name = newThreadName.trim();
-    if (!name) return;
-    createThread.mutate(
-      { name },
-      { onSuccess: () => setNewThreadName("") },
-    );
-  }
+	const openCreateThreadModal = useUIStore((s) => s.openCreateThreadModal);
+	const { data: categories } = useCategories();
+	const { data: threads, isLoading } = useThreads(activeTab === "resolved");
 
 	if (isLoading) {
 		return (
@@ -189,51 +187,165 @@ function PlanningView() {
 		);
 	}
 
+	// Filter threads by active tab and category
+	const filteredThreads = (threads ?? [])
+		.filter((t) => t.status === activeTab)
+		.filter((t) => (categoryFilter ? t.categoryId === categoryFilter : true));
+
+	// Determine if we should show the educational empty state
+	const isEmptyNoFilters =
+		filteredThreads.length === 0 &&
+		activeTab === "active" &&
+		categoryFilter === null &&
+		(!threads || threads.length === 0);
+
 	return (
 		<div>
-      {/* Create thread form */}
-      <form onSubmit={handleCreateThread} className="flex gap-2 mb-6">
-        <input
-          type="text"
-          value={newThreadName}
-          onChange={(e) => setNewThreadName(e.target.value)}
-          placeholder="New thread name..."
-          className="flex-1 px-3 py-2 border border-gray-200 rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
-        />
+			{/* Header row */}
+			<div className="flex items-center justify-between mb-4">
+				<h2 className="text-lg font-semibold text-gray-900">
+					Planning Threads
+				</h2>
 				<button
-          type="submit"
-          disabled={!newThreadName.trim() || createThread.isPending}
-          className="px-4 py-2 bg-blue-600 hover:bg-blue-700 disabled:opacity-50 text-white text-sm font-medium rounded-lg transition-colors"
+					type="button"
+					onClick={openCreateThreadModal}
+					className="inline-flex items-center gap-2 px-4 py-2 bg-blue-600 hover:bg-blue-700 text-white text-sm font-medium rounded-lg transition-colors"
 				>
-          {createThread.isPending ? "Creating..." : "Create"}
-        </button>
-      </form>
-
-      {/* Show resolved toggle */}
-      <label className="flex items-center gap-2 mb-4 text-sm text-gray-600 cursor-pointer">
-        <input
-          type="checkbox"
-          checked={showResolved}
-          onChange={(e) => setShowResolved(e.target.checked)}
-          className="rounded border-gray-300 text-blue-600 focus:ring-blue-500"
+					<svg
+						aria-hidden="true"
+						className="w-4 h-4"
+						fill="none"
+						stroke="currentColor"
+						viewBox="0 0 24 24"
+					>
+						<path
+							strokeLinecap="round"
+							strokeLinejoin="round"
+							strokeWidth={2}
+							d="M12 4v16m8-8H4"
 						/>
-        Show archived threads
-      </label>
+					</svg>
+					New Thread
+				</button>
+			</div>
 
-      {/* Thread list */}
-      {!threads || threads.length === 0 ? (
-        <div className="py-12 text-center">
-          <div className="text-4xl mb-3">🔍</div>
-          <h3 className="text-lg font-semibold text-gray-900 mb-1">
-            No planning threads yet
-          </h3>
+			{/* Filter row */}
+			<div className="flex items-center justify-between mb-6">
+				{/* Pill tabs */}
+				<div className="flex bg-gray-100 rounded-full p-0.5 gap-0.5">
+					<button
+						type="button"
+						onClick={() => setActiveTab("active")}
+						className={`px-4 py-1.5 text-sm font-medium rounded-full transition-colors ${
+							activeTab === "active"
+								? "bg-blue-600 text-white"
+								: "text-gray-600 hover:bg-gray-200"
+						}`}
+					>
+						Active
+					</button>
+					<button
+						type="button"
+						onClick={() => setActiveTab("resolved")}
+						className={`px-4 py-1.5 text-sm font-medium rounded-full transition-colors ${
+							activeTab === "resolved"
+								? "bg-blue-600 text-white"
+								: "text-gray-600 hover:bg-gray-200"
+						}`}
+					>
+						Resolved
+					</button>
+				</div>
+
+				{/* Category filter */}
+				<select
+					value={categoryFilter ?? ""}
+					onChange={(e) =>
+						setCategoryFilter(e.target.value ? Number(e.target.value) : null)
+					}
+					className="px-3 py-1.5 border border-gray-200 rounded-lg text-sm bg-white focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
+				>
+					<option value="">All categories</option>
+					{categories?.map((cat) => (
+						<option key={cat.id} value={cat.id}>
+							{cat.emoji} {cat.name}
+						</option>
+					))}
+				</select>
+			</div>
+
+			{/* Content: empty state or thread grid */}
+			{isEmptyNoFilters ? (
+				<div className="py-16">
+					<div className="max-w-lg mx-auto text-center">
+						<h2 className="text-xl font-semibold text-gray-900 mb-8">
+							Plan your next purchase
+						</h2>
+						<div className="space-y-6 text-left mb-10">
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-blue-100 text-blue-700 font-bold text-sm shrink-0">
+									1
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Create a thread</p>
 									<p className="text-sm text-gray-500">
-            Start one to research your next purchase.
+										Start a research thread for gear you're considering
 									</p>
 								</div>
+							</div>
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-blue-100 text-blue-700 font-bold text-sm shrink-0">
+									2
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Add candidates</p>
+									<p className="text-sm text-gray-500">
+										Add products you're comparing with prices and weights
+									</p>
+								</div>
+							</div>
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-blue-100 text-blue-700 font-bold text-sm shrink-0">
+									3
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Pick a winner</p>
+									<p className="text-sm text-gray-500">
+										Resolve the thread and the winner joins your collection
+									</p>
+								</div>
+							</div>
+						</div>
+						<button
+							type="button"
+							onClick={openCreateThreadModal}
+							className="inline-flex items-center gap-2 px-5 py-2.5 bg-blue-600 hover:bg-blue-700 text-white text-sm font-medium rounded-lg transition-colors"
+						>
+							<svg
+								aria-hidden="true"
+								className="w-4 h-4"
+								fill="none"
+								stroke="currentColor"
+								viewBox="0 0 24 24"
+							>
+								<path
+									strokeLinecap="round"
+									strokeLinejoin="round"
+									strokeWidth={2}
+									d="M12 4v16m8-8H4"
+								/>
+							</svg>
+							Create your first thread
+						</button>
+					</div>
+				</div>
+			) : filteredThreads.length === 0 ? (
+				<div className="py-12 text-center">
+					<p className="text-sm text-gray-500">No threads found</p>
+				</div>
 			) : (
 				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-          {threads.map((thread) => (
+					{filteredThreads.map((thread) => (
 						<ThreadCard
 							key={thread.id}
 							id={thread.id}
@@ -243,10 +355,14 @@ function PlanningView() {
 							maxPriceCents={thread.maxPriceCents}
 							createdAt={thread.createdAt}
 							status={thread.status}
+							categoryName={thread.categoryName}
+							categoryEmoji={thread.categoryEmoji}
 						/>
 					))}
 				</div>
 			)}
+
+			<CreateThreadModal />
 		</div>
 	);
 }