Add progressive web app companion for cross-platform access

Vite + TypeScript PWA that mirrors the Android app's core features:
- Pre-processed shelter data (build-time UTM33N→WGS84 conversion)
- Leaflet map with shelter markers, user location, and offline tiles
- Canvas compass arrow (ported from DirectionArrowView.kt)
- IndexedDB shelter cache with 7-day staleness check
- Service worker with CacheFirst tiles and precached app shell
- i18n for en, nb, nn (ported from Android strings.xml)
- iOS/Android compass handling with low-pass filter
- Respects user map interaction (no auto-snap on pan/zoom)
- Build revision cache-breaker for reliable SW updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pwa/node_modules/fast-uri/benchmark/string-array-to-hex-stripped.mjs

@@ -0,0 +1,24 @@
+import { Bench } from 'tinybench'
+import { stringArrayToHexStripped } from '../lib/utils.js'
+
+const benchStringArrayToHexStripped = new Bench({ name: 'stringArrayToHexStripped' })
+
+const case1 = ['0', '0', '0', '0']
+const case2 = ['0', '0', '0', '1']
+const case3 = ['0', '0', '1', '0']
+const case4 = ['0', '1', '0', '0']
+const case5 = ['1', '0', '0', '0']
+const case6 = ['1', '0', '0', '1']
+
+benchStringArrayToHexStripped.add('stringArrayToHexStripped', function () {
+  stringArrayToHexStripped(case1)
+  stringArrayToHexStripped(case2)
+  stringArrayToHexStripped(case3)
+  stringArrayToHexStripped(case4)
+  stringArrayToHexStripped(case5)
+  stringArrayToHexStripped(case6)
+})
+
+await benchStringArrayToHexStripped.run()
+console.log(benchStringArrayToHexStripped.name)
+console.table(benchStringArrayToHexStripped.table())