stats: core-7 economy page with CPI index levels, rebase and categories

- /stats/economy defaults multi-country charts to CAN KOR CHN JPN USA NLD CUW,
  with add-a-country chips and an EU 27 comparison line
- CPI index levels rebased to a chosen base year, index/YoY toggle,
  categories (food, energy, housing, core) where the source has them
- new no-key collectors: oecd (CPI categories, 10y yields), statcan (CPI);
  bis WS_LONG_CPI, FRED US CPI categories, Eurostat prc_hicp_minr, WB FP.CPI.TOTL
- Canada added as a region; CBS Curacao fallbacks for growth/unemployment
- timers stats-oecd and stats-statcan

src/lib/stats/CountryPicker.svelte

@@ -0,0 +1,96 @@
+<script lang="ts">
+	// Country chips for the multi-country charts on /stats/economy: the core seven are on by
+	// default, the extra countries can be added, and the EU 27 comparison line can be toggled.
+	import { COUNTRY } from './regions.js';
+	import { FLAG } from './countries.js';
+	import { CORE7, EXTRA } from './econ.js';
+
+	let { selected = $bindable(), eu = $bindable() }: { selected: string[]; eu: boolean } = $props();
+	const toggle = (c: string) =>
+		(selected = selected.includes(c) ? selected.filter((x) => x !== c) : [...selected, c]);
+	const isCore = $derived(
+		selected.length === CORE7.length && CORE7.every((c) => selected.includes(c))
+	);
+</script>
+
+<div class="picker" role="group" aria-label="Countries on the charts">
+	<div class="row">
+		<span class="label">core</span>
+		{#each CORE7 as c (c)}
+			<button
+				type="button"
+				class="chip"
+				aria-pressed={selected.includes(c)}
+				onclick={() => toggle(c)}
+			>
+				<span aria-hidden="true">{FLAG[c]}</span>{COUNTRY[c]}
+			</button>
+		{/each}
+		<button type="button" class="chip eu" aria-pressed={eu} onclick={() => (eu = !eu)}>
+			<span aria-hidden="true">🇪🇺</span>EU 27 line
+		</button>
+	</div>
+	<div class="row">
+		<span class="label">add</span>
+		{#each EXTRA as c (c)}
+			<button
+				type="button"
+				class="chip"
+				aria-pressed={selected.includes(c)}
+				onclick={() => toggle(c)}
+			>
+				<span aria-hidden="true">{FLAG[c]}</span>{COUNTRY[c]}
+			</button>
+		{/each}
+		{#if !isCore}
+			<button type="button" class="reset" onclick={() => (selected = [...CORE7])}>reset</button>
+		{/if}
+	</div>
+</div>
+
+<style>
+	.picker {
+		display: flex;
+		flex-direction: column;
+		gap: 0.4rem;
+		margin: 0 0 1rem;
+		padding: 0.75rem;
+		border: 1px solid var(--site-border);
+		border-radius: 0.75rem;
+		background: var(--site-bg);
+	}
+	.row {
+		display: flex;
+		flex-wrap: wrap;
+		align-items: center;
+		gap: 0.35rem;
+	}
+	.label {
+		width: 2.6rem;
+		font-size: 0.72rem;
+		text-transform: uppercase;
+		letter-spacing: 0.06em;
+		color: var(--site-muted);
+	}
+	.chip,
+	.reset {
+		display: inline-flex;
+		align-items: center;
+		gap: 0.3rem;
+		border: 1px solid var(--site-border);
+		border-radius: 999px;
+		padding: 0.2rem 0.6rem;
+		font-size: 0.8rem;
+		background: transparent;
+		color: var(--site-muted);
+		cursor: pointer;
+	}
+	.chip[aria-pressed='true'] {
+		color: var(--site-text);
+		border-color: var(--site-text);
+		background: color-mix(in srgb, var(--site-text) 8%, transparent);
+	}
+	.reset {
+		border-style: dashed;
+	}
+</style>

src/lib/stats/countries.ts

@@ -13,6 +13,7 @@ export const COUNTRY_PAGES = [
 	'BEL',
 	'GBR',
 	'JPN',
+	'CAN',
 	'IND',
 	'BRA',
 	'RUS',
@@ -34,6 +35,7 @@ export const FLAG: Record<string, string> = {
 	BEL: '🇧🇪',
 	GBR: '🇬🇧',
 	JPN: '🇯🇵',
+	CAN: '🇨🇦',
 	IND: '🇮🇳',
 	BRA: '🇧🇷',
 	RUS: '🇷🇺',
@@ -52,6 +54,7 @@ export const COUNTRY_COLOR: Record<string, string> = {
 	BEL: '#a16207',
 	GBR: '#a855f7',
 	JPN: '#ec4899',
+	CAN: '#dc2626',
 	IND: '#10b981',
 	BRA: '#84cc16',
 	RUS: '#0d9488',

src/lib/stats/econ.test.ts

@@ -0,0 +1,27 @@
+import { describe, expect, it } from 'vitest';
+import { CORE7, CPI_BY_CATEGORY, CPI_TOTAL, rebase, yearMean, yoyByDate } from './econ.js';
+
+describe('econ helpers', () => {
+	const pts: [string, number][] = [
+		['2014-12-01', 99],
+		['2015-01-01', 100],
+		['2015-07-01', 102],
+		['2016-01-01', 103],
+		['2016-07-01', 104.04]
+	];
+	it('averages a calendar year', () => expect(yearMean(pts, 2015)).toBe(101));
+	it('rebases to the base-year mean', () =>
+		expect(rebase(pts, 2015)?.[3]).toEqual(['2016-01-01', 101.98]));
+	it('returns null when the base year is missing', () => expect(rebase(pts, 2010)).toBeNull());
+	it('computes year on year by date and skips gaps', () =>
+		expect(yoyByDate(pts)).toEqual([
+			['2016-01-01', 3],
+			['2016-07-01', 2]
+		]));
+	it('covers every core country for CPI', () => {
+		for (const c of CORE7) {
+			expect(CPI_TOTAL[c]).toBeDefined();
+			expect(CPI_BY_CATEGORY[c]?.ids.total).toBeDefined();
+		}
+	});
+});

src/lib/stats/econ.ts

@@ -0,0 +1,151 @@
+// Country sets and series maps for /stats/economy. The core set (CAN, KOR, CHN, JPN, USA, NLD,
+// CUW) is the default on every multi-country chart; the extra countries can be added, and the
+// EU aggregate is kept as a comparison line. Every id points at a stored series; nothing here is
+// estimated, gaps stay gaps.
+import type { StatPoint } from './chart.js';
+
+export const CORE7 = ['CAN', 'KOR', 'CHN', 'JPN', 'USA', 'NLD', 'CUW'] as const;
+export const EXTRA = ['DEU', 'FRA', 'GBR', 'BEL', 'IND', 'BRA', 'RUS'] as const;
+export const ECON_COUNTRIES = [...CORE7, ...EXTRA] as const;
+export type EconCountry = (typeof ECON_COUNTRIES)[number];
+/** Comparison aggregates: EU 27 by default; the euro area where the data is per currency area. */
+export type Aggregate = 'EU27' | 'EA';
+
+/** All-items CPI, index level, best monthly source per region (national office first). */
+export const CPI_TOTAL: Record<string, { id: string; source: string; base: string }> = {
+	// CBS CPI as carried by the BIS long series (1965→). CBS 83131NED (2015 = 100) stops in
+	// December 2025 and 86141NED (2025 = 100) starts in December 2009, so neither covers the span.
+	NLD: { id: 'bis:cpi:NL', source: 'bis', base: '2010 = 100' },
+	USA: { id: 'fred:CPIAUCSL', source: 'fred', base: '1982–84 = 100' },
+	CAN: { id: 'statcan:cpi:total', source: 'statcan', base: '2002 = 100' },
+	JPN: { id: 'bis:cpi:JP', source: 'bis', base: '2010 = 100' },
+	KOR: { id: 'bis:cpi:KR', source: 'bis', base: '2010 = 100' },
+	CHN: { id: 'bis:cpi:CN', source: 'bis', base: '2010 = 100' },
+	CUW: { id: 'cw:cpi:index', source: 'cbscw', base: '2023 = 100' },
+	DEU: { id: 'bis:cpi:DE', source: 'bis', base: '2010 = 100' },
+	FRA: { id: 'bis:cpi:FR', source: 'bis', base: '2010 = 100' },
+	GBR: { id: 'bis:cpi:GB', source: 'bis', base: '2010 = 100' },
+	BEL: { id: 'bis:cpi:BE', source: 'bis', base: '2010 = 100' },
+	IND: { id: 'bis:cpi:IN', source: 'bis', base: '2010 = 100' },
+	BRA: { id: 'bis:cpi:BR', source: 'bis', base: '2010 = 100' },
+	RUS: { id: 'bis:cpi:RU', source: 'bis', base: '2010 = 100' },
+	EU27: {
+		id: 'eurostat:prc_hicp_minr:I15.TOTAL.EU27_2020',
+		source: 'eurostat',
+		base: '2015 = 100'
+	},
+	EA: { id: 'eurostat:prc_hicp_minr:I15.TOTAL.EA20', source: 'eurostat', base: '2015 = 100' }
+};
+
+export const CPI_CATS = ['total', 'food', 'housing', 'energy', 'core'] as const;
+export type CpiCat = (typeof CPI_CATS)[number];
+export const CPI_CAT_LABEL: Record<CpiCat, string> = {
+	total: 'All items',
+	food: 'Food',
+	housing: 'Housing',
+	energy: 'Energy',
+	core: 'Core (excl. food and energy)'
+};
+const hicp = (g: string): Record<CpiCat, string> => ({
+	total: `eurostat:prc_hicp_minr:I15.TOTAL.${g}`,
+	food: `eurostat:prc_hicp_minr:I15.CP01.${g}`,
+	housing: `eurostat:prc_hicp_minr:I15.CP04.${g}`,
+	energy: `eurostat:prc_hicp_minr:I15.NRG.${g}`,
+	core: `eurostat:prc_hicp_minr:I15.TOT_X_NRG_FOOD.${g}`
+});
+const oecd = (c: string, cats: CpiCat[]) =>
+	Object.fromEntries(cats.map((k) => [k, `oecd:cpi:${c}:${k}`])) as Partial<Record<CpiCat, string>>;
+
+/** CPI by main category where the source publishes it. */
+export const CPI_BY_CATEGORY: Record<
+	string,
+	{ ids: Partial<Record<CpiCat, string>>; source: string; note: string }
+> = {
+	NLD: { ids: hicp('NL'), source: 'eurostat', note: 'HICP (Eurostat), 2015 = 100' },
+	USA: {
+		ids: {
+			total: 'fred:CPIAUCSL',
+			food: 'fred:CPIUFDSL',
+			housing: 'fred:CPIHOSSL',
+			energy: 'fred:CPIENGSL',
+			core: 'fred:CPILFESL'
+		},
+		source: 'fred',
+		note: 'BLS CPI-U, seasonally adjusted, via FRED'
+	},
+	CAN: {
+		ids: Object.fromEntries(CPI_CATS.map((k) => [k, `statcan:cpi:${k}`])),
+		source: 'statcan',
+		note: 'Statistics Canada 18-10-0004-01; housing = shelter'
+	},
+	KOR: {
+		ids: oecd('KOR', [...CPI_CATS]),
+		source: 'oecd',
+		note: 'OECD prices database'
+	},
+	JPN: {
+		ids: oecd('JPN', [...CPI_CATS]),
+		source: 'oecd',
+		note: 'OECD prices database; the OECD series for Japan stop in June 2021'
+	},
+	CHN: {
+		ids: oecd('CHN', ['total', 'food']),
+		source: 'oecd',
+		note: 'OECD prices database: all items and food only (other NBS categories are manual)'
+	},
+	CUW: {
+		ids: { total: 'cw:cpi:index' },
+		source: 'cbscw',
+		note: 'CBS Curaçao: all items only'
+	},
+	EU27: { ids: hicp('EU27_2020'), source: 'eurostat', note: 'HICP (Eurostat), 2015 = 100' },
+	EA: { ids: hicp('EA20'), source: 'eurostat', note: 'HICP (Eurostat), 2015 = 100' }
+};
+
+/** BIS policy rate area per country (euro members → ECB); missing = no BIS series. */
+export const POLICY_RATE: Record<string, string> = {
+	CAN: 'CA',
+	KOR: 'KR',
+	CHN: 'CN',
+	JPN: 'JP',
+	USA: 'US',
+	NLD: 'XM',
+	GBR: 'GB',
+	EA: 'XM'
+};
+
+/** Annual macro indicators: IMF WEO first, then CBS Curaçao for Curaçao, then the World Bank. */
+export const ANNUAL = {
+	growth: { imf: 'NGDP_RPCH', wb: 'NY.GDP.MKTP.KD.ZG', cw: 'cw:gdp:real_growth_pct' },
+	unemployment: {
+		imf: 'LUR',
+		wb: 'SL.UEM.TOTL.ZS',
+		cw: 'cw:lfs:unemployment_rate_pct:total'
+	},
+	debt: { imf: 'GGXWDG_NGDP', wb: 'GC.DOD.TOTL.GD.ZS', cw: null },
+	trade: { imf: null, wb: 'NE.TRD.GNFS.ZS', cw: null }
+} as const;
+
+/** Mean of the points in a calendar year, or null when the year has no observations. */
+export function yearMean(points: StatPoint[], year: number): number | null {
+	const vals = points.filter(([d]) => d.startsWith(`${year}-`)).map(([, v]) => v);
+	return vals.length ? vals.reduce((a, b) => a + b, 0) / vals.length : null;
+}
+
+/** Rebase an index to (base year average) = 100. Null when the base year is not covered. */
+export function rebase(points: StatPoint[], year: number): StatPoint[] | null {
+	const base = yearMean(points, year);
+	if (!base) return null;
+	return points.map(([d, v]) => [d, Math.round((v / base) * 10000) / 100]);
+}
+
+/** Year-on-year % change by date (same month a year earlier); missing months stay missing. */
+export function yoyByDate(points: StatPoint[]): StatPoint[] {
+	const map = new Map(points);
+	const out: StatPoint[] = [];
+	for (const [d, v] of points) {
+		const prev = map.get(`${Number(d.slice(0, 4)) - 1}${d.slice(4)}`);
+		if (prev) out.push([d, Math.round(((v - prev) / prev) * 10000) / 100]);
+	}
+	return out;
+}

src/lib/stats/regions.ts

@@ -19,6 +19,7 @@ export const COUNTRY: Record<string, string> = {
 	CN: 'China',
 	GB: 'United Kingdom',
 	JP: 'Japan',
+	CA: 'Canada',
 	NLD: 'Netherlands',
 	USA: 'United States',
 	KOR: 'South Korea',
@@ -31,6 +32,7 @@ export const COUNTRY: Record<string, string> = {
 	BEL: 'Belgium',
 	GBR: 'United Kingdom',
 	JPN: 'Japan',
+	CAN: 'Canada',
 	IND: 'India',
 	BRA: 'Brazil',
 	RUS: 'Russia',