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-plugin-polyfill-corejs3/lib/utils.js

@@ -0,0 +1,63 @@
+"use strict";
+
+exports.__esModule = true;
+exports.BABEL_RUNTIME = void 0;
+exports.callMethod = callMethod;
+exports.coreJSModule = coreJSModule;
+exports.coreJSPureHelper = coreJSPureHelper;
+exports.extractOptionalCheck = extractOptionalCheck;
+exports.isCoreJSSource = isCoreJSSource;
+exports.maybeMemoizeContext = maybeMemoizeContext;
+var _babel = _interopRequireWildcard(require("@babel/core"));
+var _entries = _interopRequireDefault(require("../core-js-compat/entries.js"));
+function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
+function _interopRequireWildcard(e, t) { if ("function" == typeof WeakMap) var r = new WeakMap(), n = new WeakMap(); return (_interopRequireWildcard = function (e, t) { if (!t && e && e.__esModule) return e; var o, i, f = { __proto__: null, default: e }; if (null === e || "object" != typeof e && "function" != typeof e) return f; if (o = t ? n : r) { if (o.has(e)) return o.get(e); o.set(e, f); } for (const t in e) "default" !== t && {}.hasOwnProperty.call(e, t) && ((i = (o = Object.defineProperty) && Object.getOwnPropertyDescriptor(e, t)) && (i.get || i.set) ? o(f, t, i) : f[t] = e[t]); return f; })(e, t); }
+const {
+  types: t
+} = _babel.default || _babel;
+const BABEL_RUNTIME = exports.BABEL_RUNTIME = "@babel/runtime-corejs3";
+function callMethod(path, id, optionalCall, wrapCallee) {
+  const [context1, context2] = maybeMemoizeContext(path.node, path.scope);
+  let callee = t.callExpression(id, [context1]);
+  if (wrapCallee) callee = wrapCallee(callee);
+  const call = t.identifier("call");
+  path.replaceWith(optionalCall ? t.optionalMemberExpression(callee, call, false, true) : t.memberExpression(callee, call));
+  path.parentPath.unshiftContainer("arguments", context2);
+}
+function maybeMemoizeContext(node, scope) {
+  const {
+    object
+  } = node;
+  let context1, context2;
+  if (t.isIdentifier(object)) {
+    context2 = object;
+    context1 = t.cloneNode(object);
+  } else {
+    context2 = scope.generateDeclaredUidIdentifier("context");
+    context1 = t.assignmentExpression("=", t.cloneNode(context2), object);
+  }
+  return [context1, context2];
+}
+function extractOptionalCheck(scope, node) {
+  let optionalNode = node;
+  while (!optionalNode.optional && t.isOptionalMemberExpression(optionalNode.object)) {
+    optionalNode = optionalNode.object;
+  }
+  optionalNode.optional = false;
+  const ctx = scope.generateDeclaredUidIdentifier("context");
+  const assign = t.assignmentExpression("=", ctx, optionalNode.object);
+  optionalNode.object = t.cloneNode(ctx);
+  return ifNotNullish => t.conditionalExpression(t.binaryExpression("==", assign, t.nullLiteral()), t.unaryExpression("void", t.numericLiteral(0)), ifNotNullish);
+}
+function isCoreJSSource(source) {
+  if (typeof source === "string") {
+    source = source.replace(/\\/g, "/").replace(/(\/(index)?)?(\.js)?$/i, "").toLowerCase();
+  }
+  return Object.prototype.hasOwnProperty.call(_entries.default, source) && _entries.default[source];
+}
+function coreJSModule(name) {
+  return `core-js/modules/${name}.js`;
+}
+function coreJSPureHelper(name, useBabelRuntime, ext) {
+  return useBabelRuntime ? `${BABEL_RUNTIME}/core-js/${name}${ext}` : `core-js-pure/features/${name}.js`;
+}