Add /notes: dated, data-linked board notes

.gitignore

@@ -12,6 +12,8 @@ results/ground_truth.csv
 results/scenarios.csv
 output/
 data/
+!notes/data/
+!notes/data/**
 # Committed sensitivity evidence (pinned by tests/test_sensitivity_evidence.py)
 !sensitivity/data/
 

app/src/App.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import Link from "next/link";
 import {
   useCallback,
   useEffect,
@@ -353,6 +354,10 @@ export default function App() {
         availableViews={availableViews}
         navItems={navItems}
         activeNav={activeNav}
+        actionLinks={[
+          { label: "Paper", href: "/paper", type: "internal" },
+          { label: "Notes", href: "/notes", type: "internal" },
+        ]}
         versionId={versionId}
         pendingVersionId={pendingVersionId}
         onSelectVersion={handleSelectVersion}
@@ -442,6 +447,13 @@ export default function App() {
             Paper
           </a>{" "}
           &middot;{" "}
+          <Link
+            href="/notes"
+            className="text-text-secondary hover:text-primary transition-colors"
+          >
+            Notes
+          </Link>{" "}
+          &middot;{" "}
           <a
             href="https://policyengine.org"
             className="text-text-secondary hover:text-primary transition-colors"
@@ -461,7 +473,8 @@ export default function App() {
             className="text-text-secondary hover:text-primary transition-colors"
           >
             Expand
-          </a>
+          </a>{" "}
+          &middot;{" "}
           <a
             href="https://github.com/PolicyEngine/policybench"
             className="text-text-secondary hover:text-primary transition-colors"

app/src/app/model/[id]/page.tsx

@@ -162,7 +162,11 @@ export default async function ModelPage({
   return (
     <main id="main" className="min-h-screen bg-void">
       <SiteHeader
-        actionLink={{ label: "Leaderboard", href: "/", type: "internal" }}
+        actionLinks={[
+          { label: "Leaderboard", href: "/", type: "internal" },
+          { label: "Paper", href: "/paper", type: "internal" },
+          { label: "Notes", href: "/notes", type: "internal" },
+        ]}
         expandedContent={expanded}
         alwaysExpanded
       />

app/src/app/notes/[slug]/page.tsx

@@ -0,0 +1,76 @@
+import type { Metadata } from "next";
+import { notFound } from "next/navigation";
+
+import { NoteArticle, interpolateNoteText } from "../../../components/NotesContent";
+import SiteHeader from "../../../components/SiteHeader";
+import { getNote, notes } from "../../../notes";
+
+export const dynamicParams = false;
+
+export function generateStaticParams() {
+  return notes.map((note) => ({ slug: note.slug }));
+}
+
+export async function generateMetadata({
+  params,
+}: {
+  params: Promise<{ slug: string }>;
+}): Promise<Metadata> {
+  const { slug } = await params;
+  const note = getNote(slug);
+  if (!note) notFound();
+  const description = interpolateNoteText(note, note.paragraphs[0]);
+  const url = `https://policybench.org/notes/${note.slug}`;
+  return {
+    title: note.title,
+    description,
+    alternates: { canonical: `/notes/${note.slug}` },
+    openGraph: {
+      type: "article",
+      url,
+      siteName: "PolicyBench",
+      title: note.title,
+      description,
+      publishedTime: note.date,
+      images: [
+        {
+          url: "/og-image.png",
+          width: 1200,
+          height: 630,
+          alt: "PolicyBench — an LLM benchmark for tax and benefit calculation",
+        },
+      ],
+    },
+    twitter: {
+      card: "summary_large_image",
+      title: note.title,
+      description,
+      images: ["/og-image.png"],
+    },
+  };
+}
+
+export default async function NotePage({
+  params,
+}: {
+  params: Promise<{ slug: string }>;
+}) {
+  const { slug } = await params;
+  const note = getNote(slug);
+  if (!note) notFound();
+
+  return (
+    <main id="main" className="min-h-screen bg-void">
+      <SiteHeader
+        actionLinks={[
+          { label: "Leaderboard", href: "/", type: "internal" },
+          { label: "Paper", href: "/paper", type: "internal" },
+        ]}
+        alwaysExpanded
+      />
+      <div className="mx-auto max-w-3xl px-4 pb-20 pt-10 sm:px-6 sm:pt-14">
+        <NoteArticle note={note} titleLevel="h1" />
+      </div>
+    </main>
+  );
+}

app/src/app/notes/page.tsx

@@ -0,0 +1,63 @@
+import type { Metadata } from "next";
+
+import {
+  NOTES_INTRO,
+  NotesPageContent,
+} from "../../components/NotesContent";
+import SiteHeader from "../../components/SiteHeader";
+
+export const metadata: Metadata = {
+  title: "Notes",
+  description: NOTES_INTRO,
+  alternates: {
+    canonical: "/notes",
+  },
+  openGraph: {
+    type: "website",
+    url: "https://policybench.org/notes",
+    siteName: "PolicyBench",
+    title: "PolicyBench notes",
+    description: NOTES_INTRO,
+    images: [
+      {
+        url: "/og-image.png",
+        width: 1200,
+        height: 630,
+        alt: "PolicyBench — an LLM benchmark for tax and benefit calculation",
+      },
+    ],
+  },
+  twitter: {
+    card: "summary_large_image",
+    title: "PolicyBench notes",
+    description: NOTES_INTRO,
+    images: ["/og-image.png"],
+  },
+};
+
+export default function NotesPage() {
+  const expanded = (
+    <>
+      <h1 className="font-[family-name:var(--font-display)] text-3xl tracking-tight text-text sm:text-4xl">
+        Notes
+      </h1>
+      <p className="mt-4 max-w-2xl text-sm leading-relaxed text-text-secondary sm:text-base">
+        {NOTES_INTRO}
+      </p>
+    </>
+  );
+
+  return (
+    <main id="main" className="min-h-screen bg-void">
+      <SiteHeader
+        actionLinks={[
+          { label: "Leaderboard", href: "/", type: "internal" },
+          { label: "Paper", href: "/paper", type: "internal" },
+        ]}
+        expandedContent={expanded}
+        alwaysExpanded
+      />
+      <NotesPageContent />
+    </main>
+  );
+}

app/src/app/paper/page.tsx

@@ -69,11 +69,10 @@ export default function PaperPage() {
     <main id="main" className="min-h-screen bg-void">
       <h1 className="sr-only">PolicyBench paper</h1>
       <SiteHeader
-        actionLink={{
-          label: "Benchmark",
-          href: "/",
-          type: "internal",
-        }}
+        actionLinks={[
+          { label: "Leaderboard", href: "/", type: "internal" },
+          { label: "Notes", href: "/notes", type: "internal" },
+        ]}
         expandedContent={expanded}
         alwaysExpanded
       />

app/src/app/sitemap.ts

@@ -2,6 +2,7 @@ import type { MetadataRoute } from "next";
 
 import rawData from "../data-summary.json";
 import { listModels } from "../lib/modelPage";
+import { notes } from "../notes";
 import type { DashboardBundle } from "../types";
 
 export default function sitemap(): MetadataRoute.Sitemap {
@@ -10,6 +11,11 @@ export default function sitemap(): MetadataRoute.Sitemap {
     changeFrequency: "monthly" as const,
     priority: 0.6,
   }));
+  const noteEntries = notes.map((note) => ({
+    url: `https://policybench.org/notes/${note.slug}`,
+    changeFrequency: "monthly" as const,
+    priority: 0.5,
+  }));
   return [
     {
       url: "https://policybench.org/",
@@ -21,11 +27,17 @@ export default function sitemap(): MetadataRoute.Sitemap {
       changeFrequency: "monthly",
       priority: 0.7,
     },
+    {
+      url: "https://policybench.org/notes",
+      changeFrequency: "weekly",
+      priority: 0.7,
+    },
     {
       url: "https://policybench.org/expand",
       changeFrequency: "monthly",
       priority: 0.5,
     },
+    ...noteEntries,
     ...modelEntries,
   ];
 }

app/src/components/Hero.tsx

@@ -1,6 +1,9 @@
 import { DEFAULT_VERSION_ID } from "../lib/dataVersionsRuntime";
 import type { BenchData, CountryCode } from "../types";
-import SiteHeader, { type HeaderNavItem } from "./SiteHeader";
+import SiteHeader, {
+  type HeaderActionLink,
+  type HeaderNavItem,
+} from "./SiteHeader";
 
 export default function Hero({
   selectedView,
@@ -9,6 +12,7 @@ export default function Hero({
   availableViews,
   navItems,
   activeNav,
+  actionLinks,
   versionId,
   pendingVersionId,
   onSelectVersion,
@@ -20,6 +24,7 @@ export default function Hero({
   availableViews: CountryCode[];
   navItems: readonly HeaderNavItem[];
   activeNav: string;
+  actionLinks: readonly HeaderActionLink[];
   versionId: string;
   pendingVersionId: string | null;
   onSelectVersion: (id: string) => void;
@@ -56,7 +61,7 @@ export default function Hero({
         versionId={versionId}
         pendingVersionId={pendingVersionId}
         onSelectVersion={onSelectVersion}
-        actionLink={{ label: "Paper", href: "/paper", type: "internal" }}
+        actionLinks={actionLinks}
       />
 
       <section