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/tsx/dist/client-BQVF1NaW.mjs

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+var a=Object.defineProperty;var o=(e,n)=>a(e,"name",{value:n,configurable:!0});import p from"node:net";import{g}from"./get-pipe-path-BHW2eJdv.mjs";const m=o(()=>new Promise(e=>{const n=g(process.ppid),t=p.createConnection(n,()=>{e(o(i=>{const r=Buffer.from(JSON.stringify(i)),s=Buffer.alloc(4);s.writeInt32BE(r.length,0),t.write(Buffer.concat([s,r]))},"sendToParent"))});t.on("error",()=>{e()}),t.unref()}),"connectToServer"),c={send:void 0},f=m();f.then(e=>{c.send=e},()=>{});export{f as c,c as p};