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/@babel/helper-define-polyfill-provider/lib/debug-utils.js

@@ -0,0 +1,14 @@
+"use strict";
+
+exports.__esModule = true;
+exports.presetEnvSilentDebugHeader = void 0;
+exports.stringifyTargets = stringifyTargets;
+exports.stringifyTargetsMultiline = stringifyTargetsMultiline;
+var _helperCompilationTargets = require("@babel/helper-compilation-targets");
+const presetEnvSilentDebugHeader = exports.presetEnvSilentDebugHeader = "#__secret_key__@babel/preset-env__don't_log_debug_header_and_resolved_targets";
+function stringifyTargetsMultiline(targets) {
+  return JSON.stringify((0, _helperCompilationTargets.prettifyTargets)(targets), null, 2);
+}
+function stringifyTargets(targets) {
+  return JSON.stringify(targets).replace(/,/g, ", ").replace(/^\{"/, '{ "').replace(/"\}$/, '" }');
+}