Fix categories

hdyc-svelte/src/lib/components/Sidebar.svelte

@@ -2,7 +2,7 @@
   import { browser } from '$app/environment';
   import { onMount } from 'svelte';
   import { page } from '$app/stores';
-  import { categories, getCalculatorsByCategory, type CalculatorDef } from '$lib/data/calculators';
+  import { categories, categoryOrder, getCalculatorsByCategory, type CalculatorDef } from '$lib/data/calculators';
 
   let expandedCategory = '';
   let expandedUnits: Record<string, string> = {};
@@ -31,18 +31,21 @@
     conversions: CalculatorDef[];
   };
 
-  $: categoryUnitGroups = Object.entries(categories).map(([key, meta]) => {
+  $: categoryUnitGroups = categoryOrder
+    .map(key => {
+      const meta = categories[key];
+      if (!meta) return null;
       const buckets = new Map<string, UnitBucket>();
       const calcs = getCalculatorsByCategory(key);
 
       calcs.forEach(calc => {
         [calc.labels.in1, calc.labels.in2].forEach(unit => {
-        const key = unit.toLowerCase();
-        const existing = buckets.get(key);
+          const lower = unit.toLowerCase();
+          const existing = buckets.get(lower);
           if (existing) {
             existing.conversions.push(calc);
           } else {
-          buckets.set(key, {
+            buckets.set(lower, {
               label: unit,
               conversions: [calc],
             });
@@ -58,7 +61,8 @@
         }));
 
       return { key, meta, units };
-  });
+    })
+    .filter(Boolean);
 
   function toggle(cat: string) {
     const wasOpen = expandedCategory === cat;

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

@@ -39,6 +39,29 @@ export const categories: Record<string, { label: string; icon: string }> = {
   other:           { label: 'Other',               icon: '🔄' },
 };
 
+export const categoryOrder = [
+  'length',
+  'weight',
+  'temperature',
+  'volume',
+  'fluids',
+  'area',
+  'speed',
+  'pressure',
+  'energy',
+  'magnetism',
+  'power',
+  'data',
+  'time',
+  'angle',
+  'number-systems',
+  'radiation',
+  'electrical',
+  'force',
+  'light',
+  'other',
+] as const;
+
 export const calculators: CalculatorDef[] = [
   {"slug": "inches-to-feet", "name": "Inches to Feet", "category": "length", "type": "standard", "teaser": "If a shelf spans 36 inches, how many feet of trim does it cover?", "labels": {"in1": "Inches", "in2": "Feet"}, "factor": 12.0},
   {"slug": "kilograms-to-pounds", "name": "Kilograms to Pounds", "category": "weight", "type": "standard", "labels": {"in1": "Kilograms", "in2": "Pounds"}, "factor": 2.20462262},
@@ -1319,11 +1342,14 @@ export function getCalculatorsByCategory(category: string): CalculatorDef[] {
 }
 
 export function getCategoriesWithCounts(): { key: string; label: string; icon: string; count: number }[] {
-  return Object.entries(categories).map(([key, meta]) => ({
-    key,
-    ...meta,
-    count: calculators.filter(c => c.category === key && !c.hidden).length,
-  }));
+  return categoryOrder
+    .map(key => {
+      const meta = categories[key];
+      if (!meta) return null;
+      const count = calculators.filter(c => c.category === key && !c.hidden).length;
+      return { key, ...meta, count };
+    })
+    .filter(Boolean) as { key: string; label: string; icon: string; count: number }[];
 }
 
 export function searchCalculators(query: string): CalculatorDef[] {