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/is-stream/index.d.ts

@@ -0,0 +1,79 @@
+import * as stream from 'stream';
+
+declare const isStream: {
+	/**
+	@returns Whether `stream` is a [`Stream`](https://nodejs.org/api/stream.html#stream_stream).
+
+	@example
+	```
+	import * as fs from 'fs';
+	import isStream = require('is-stream');
+
+	isStream(fs.createReadStream('unicorn.png'));
+	//=> true
+
+	isStream({});
+	//=> false
+	```
+	*/
+	(stream: unknown): stream is stream.Stream;
+
+	/**
+	@returns Whether `stream` is a [`stream.Writable`](https://nodejs.org/api/stream.html#stream_class_stream_writable).
+
+	@example
+	```
+	import * as fs from 'fs';
+	import isStream = require('is-stream');
+
+	isStream.writable(fs.createWriteStrem('unicorn.txt'));
+	//=> true
+	```
+	*/
+	writable(stream: unknown): stream is stream.Writable;
+
+	/**
+	@returns Whether `stream` is a [`stream.Readable`](https://nodejs.org/api/stream.html#stream_class_stream_readable).
+
+	@example
+	```
+	import * as fs from 'fs';
+	import isStream = require('is-stream');
+
+	isStream.readable(fs.createReadStream('unicorn.png'));
+	//=> true
+	```
+	*/
+	readable(stream: unknown): stream is stream.Readable;
+
+	/**
+	@returns Whether `stream` is a [`stream.Duplex`](https://nodejs.org/api/stream.html#stream_class_stream_duplex).
+
+	@example
+	```
+	import {Duplex} from 'stream';
+	import isStream = require('is-stream');
+
+	isStream.duplex(new Duplex());
+	//=> true
+	```
+	*/
+	duplex(stream: unknown): stream is stream.Duplex;
+
+	/**
+	@returns Whether `stream` is a [`stream.Transform`](https://nodejs.org/api/stream.html#stream_class_stream_transform).
+
+	@example
+	```
+	import * as fs from 'fs';
+	import Stringify = require('streaming-json-stringify');
+	import isStream = require('is-stream');
+
+	isStream.transform(Stringify());
+	//=> true
+	```
+	*/
+	transform(input: unknown): input is stream.Transform;
+};
+
+export = isStream;

pwa/node_modules/is-stream/index.js

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+'use strict';
+
+const isStream = stream =>
+	stream !== null &&
+	typeof stream === 'object' &&
+	typeof stream.pipe === 'function';
+
+isStream.writable = stream =>
+	isStream(stream) &&
+	stream.writable !== false &&
+	typeof stream._write === 'function' &&
+	typeof stream._writableState === 'object';
+
+isStream.readable = stream =>
+	isStream(stream) &&
+	stream.readable !== false &&
+	typeof stream._read === 'function' &&
+	typeof stream._readableState === 'object';
+
+isStream.duplex = stream =>
+	isStream.writable(stream) &&
+	isStream.readable(stream);
+
+isStream.transform = stream =>
+	isStream.duplex(stream) &&
+	typeof stream._transform === 'function';
+
+module.exports = isStream;

pwa/node_modules/is-stream/license

@@ -0,0 +1,9 @@
+MIT License
+
+Copyright (c) Sindre Sorhus <sindresorhus@gmail.com> (https://sindresorhus.com)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

pwa/node_modules/is-stream/package.json

@@ -0,0 +1,42 @@
+{
+	"name": "is-stream",
+	"version": "2.0.1",
+	"description": "Check if something is a Node.js stream",
+	"license": "MIT",
+	"repository": "sindresorhus/is-stream",
+	"funding": "https://github.com/sponsors/sindresorhus",
+	"author": {
+		"name": "Sindre Sorhus",
+		"email": "sindresorhus@gmail.com",
+		"url": "https://sindresorhus.com"
+	},
+	"engines": {
+		"node": ">=8"
+	},
+	"scripts": {
+		"test": "xo && ava && tsd"
+	},
+	"files": [
+		"index.js",
+		"index.d.ts"
+	],
+	"keywords": [
+		"stream",
+		"type",
+		"streams",
+		"writable",
+		"readable",
+		"duplex",
+		"transform",
+		"check",
+		"detect",
+		"is"
+	],
+	"devDependencies": {
+		"@types/node": "^11.13.6",
+		"ava": "^1.4.1",
+		"tempy": "^0.3.0",
+		"tsd": "^0.7.2",
+		"xo": "^0.24.0"
+	}
+}

pwa/node_modules/is-stream/readme.md

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+# is-stream
+
+> Check if something is a [Node.js stream](https://nodejs.org/api/stream.html)
+
+## Install
+
+```
+$ npm install is-stream
+```
+
+## Usage
+
+```js
+const fs = require('fs');
+const isStream = require('is-stream');
+
+isStream(fs.createReadStream('unicorn.png'));
+//=> true
+
+isStream({});
+//=> false
+```
+
+## API
+
+### isStream(stream)
+
+Returns a `boolean` for whether it's a [`Stream`](https://nodejs.org/api/stream.html#stream_stream).
+
+#### isStream.writable(stream)
+
+Returns a `boolean` for whether it's a [`stream.Writable`](https://nodejs.org/api/stream.html#stream_class_stream_writable).
+
+#### isStream.readable(stream)
+
+Returns a `boolean` for whether it's a [`stream.Readable`](https://nodejs.org/api/stream.html#stream_class_stream_readable).
+
+#### isStream.duplex(stream)
+
+Returns a `boolean` for whether it's a [`stream.Duplex`](https://nodejs.org/api/stream.html#stream_class_stream_duplex).
+
+#### isStream.transform(stream)
+
+Returns a `boolean` for whether it's a [`stream.Transform`](https://nodejs.org/api/stream.html#stream_class_stream_transform).
+
+## Related
+
+- [is-file-stream](https://github.com/jamestalmage/is-file-stream) - Detect if a stream is a file stream
+
+---
+
+<div align="center">
+	<b>
+		<a href="https://tidelift.com/subscription/pkg/npm-is-stream?utm_source=npm-is-stream&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
+	</b>
+	<br>
+	<sub>
+		Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
+	</sub>
+</div>