stats: /stats overview, economy, energy and Gouda pages; CBS series map; nav, homepage, /start and sitemap links

- CBS_SERIES: CPI, household tariffs (2007-now), energy balance, renewables, heat pumps,
  solar, cars, population (monthly, since 1942, components), house prices, housing stock,
  municipal levies for Gouda and its neighbours
- shared StatChart/Kpi/chart helpers with per-chart source attribution
- drop Eurostat nrg_pc_20x_h (404; CBS covers that history)

scripts/stats/eurostat.ts

@@ -64,8 +64,6 @@ export const EUROSTAT_DATASETS: Dataset[] = [
 		theme: 'energy',
 		params: { nrg_cons: 'GJ20-199', currency: 'EUR', unit: 'KWH' }
 	},
-	{ code: 'nrg_pc_204_h', theme: 'energy', params: { consom: '4161902', currency: 'EUR' } },
-	{ code: 'nrg_pc_202_h', theme: 'energy', params: { consom: '4141902', currency: 'EUR' } },
 	{ code: 'nrg_ind_id', theme: 'energy', params: { siec: 'TOTAL' } },
 	{
 		code: 'irt_lt_mcby_m',