Add centralized unit definitions

hdyc-svelte/src/lib/data/unitDefinitions.ts

@@ -0,0 +1,54 @@
+import { calculators } from './calculators';
+
+const domainDescriptions: Record<string, string> = {
+  length: 'linear or spatial distance measurement',
+  weight: 'mass or force quantity',
+  temperature: 'thermal energy level',
+  volume: 'three-dimensional capacity',
+  area: 'two-dimensional surface measurement',
+  speed: 'rate of change of position',
+  pressure: 'force exerted per unit area',
+  energy: 'capacity to do work',
+  power: 'rate of energy transfer',
+  data: 'digital information volume',
+  time: 'temporal duration',
+  angle: 'angular measurement',
+  'number-systems': 'numeric representation systems',
+  radiation: 'ionizing emission metrics',
+  electrical: 'electricity-related magnitude',
+  force: 'force or torque measurement',
+  light: 'luminous intensity',
+  other: 'specialized measurement',
+};
+
+const definitions: Record<string, string> = {};
+
+const formatLabel = (label: string): string => {
+  if (!label) return '';
+  return label
+    .replace(/\b([A-Z])/g, ' $1')
+    .replace(/\s+/g, ' ')
+    .trim();
+};
+
+const buildDefinition = (label: string, categoryKey: string): string => {
+  if (!label) return '';
+  const desc = domainDescriptions[categoryKey] || 'measurement';
+  return `${label} is used to express ${desc}. Understanding ${label} keeps calculations aligned across the ${categoryKey} domain.`;
+};
+
+calculators.forEach(calc => {
+  const { category, labels } = calc;
+  Object.values(labels).forEach(label => {
+    if (!label) return;
+    if (!definitions[label]) {
+      definitions[label] = buildDefinition(label, category);
+    }
+  });
+});
+
+export function getDefinition(label: string): string | undefined {
+  return definitions[label];
+}
+
+export const unitDefinitions = definitions;