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/es-abstract/2021/CompletionRecord.js

@@ -0,0 +1,48 @@
+'use strict';
+
+var $SyntaxError = require('es-errors/syntax');
+
+var SLOT = require('internal-slot');
+
+// https://262.ecma-international.org/7.0/#sec-completion-record-specification-type
+
+var CompletionRecord = function CompletionRecord(type, value) {
+	if (!(this instanceof CompletionRecord)) {
+		return new CompletionRecord(type, value);
+	}
+	if (type !== 'normal' && type !== 'break' && type !== 'continue' && type !== 'return' && type !== 'throw') {
+		throw new $SyntaxError('Assertion failed: `type` must be one of "normal", "break", "continue", "return", or "throw"');
+	}
+	SLOT.set(this, '[[Type]]', type);
+	SLOT.set(this, '[[Value]]', value);
+	// [[Target]] slot?
+};
+
+CompletionRecord.prototype.type = function Type() {
+	return SLOT.get(this, '[[Type]]');
+};
+
+CompletionRecord.prototype.value = function Value() {
+	return SLOT.get(this, '[[Value]]');
+};
+
+CompletionRecord.prototype['?'] = function ReturnIfAbrupt() {
+	var type = SLOT.get(this, '[[Type]]');
+	var value = SLOT.get(this, '[[Value]]');
+
+	if (type === 'throw') {
+		throw value;
+	}
+	return value;
+};
+
+CompletionRecord.prototype['!'] = function assert() {
+	var type = SLOT.get(this, '[[Type]]');
+
+	if (type !== 'normal') {
+		throw new $SyntaxError('Assertion failed: Completion Record is not of type "normal"');
+	}
+	return SLOT.get(this, '[[Value]]');
+};
+
+module.exports = CompletionRecord;