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/ms/index.js

@@ -0,0 +1,162 @@
+/**
+ * Helpers.
+ */
+
+var s = 1000;
+var m = s * 60;
+var h = m * 60;
+var d = h * 24;
+var w = d * 7;
+var y = d * 365.25;
+
+/**
+ * Parse or format the given `val`.
+ *
+ * Options:
+ *
+ *  - `long` verbose formatting [false]
+ *
+ * @param {String|Number} val
+ * @param {Object} [options]
+ * @throws {Error} throw an error if val is not a non-empty string or a number
+ * @return {String|Number}
+ * @api public
+ */
+
+module.exports = function (val, options) {
+  options = options || {};
+  var type = typeof val;
+  if (type === 'string' && val.length > 0) {
+    return parse(val);
+  } else if (type === 'number' && isFinite(val)) {
+    return options.long ? fmtLong(val) : fmtShort(val);
+  }
+  throw new Error(
+    'val is not a non-empty string or a valid number. val=' +
+      JSON.stringify(val)
+  );
+};
+
+/**
+ * Parse the given `str` and return milliseconds.
+ *
+ * @param {String} str
+ * @return {Number}
+ * @api private
+ */
+
+function parse(str) {
+  str = String(str);
+  if (str.length > 100) {
+    return;
+  }
+  var match = /^(-?(?:\d+)?\.?\d+) *(milliseconds?|msecs?|ms|seconds?|secs?|s|minutes?|mins?|m|hours?|hrs?|h|days?|d|weeks?|w|years?|yrs?|y)?$/i.exec(
+    str
+  );
+  if (!match) {
+    return;
+  }
+  var n = parseFloat(match[1]);
+  var type = (match[2] || 'ms').toLowerCase();
+  switch (type) {
+    case 'years':
+    case 'year':
+    case 'yrs':
+    case 'yr':
+    case 'y':
+      return n * y;
+    case 'weeks':
+    case 'week':
+    case 'w':
+      return n * w;
+    case 'days':
+    case 'day':
+    case 'd':
+      return n * d;
+    case 'hours':
+    case 'hour':
+    case 'hrs':
+    case 'hr':
+    case 'h':
+      return n * h;
+    case 'minutes':
+    case 'minute':
+    case 'mins':
+    case 'min':
+    case 'm':
+      return n * m;
+    case 'seconds':
+    case 'second':
+    case 'secs':
+    case 'sec':
+    case 's':
+      return n * s;
+    case 'milliseconds':
+    case 'millisecond':
+    case 'msecs':
+    case 'msec':
+    case 'ms':
+      return n;
+    default:
+      return undefined;
+  }
+}
+
+/**
+ * Short format for `ms`.
+ *
+ * @param {Number} ms
+ * @return {String}
+ * @api private
+ */
+
+function fmtShort(ms) {
+  var msAbs = Math.abs(ms);
+  if (msAbs >= d) {
+    return Math.round(ms / d) + 'd';
+  }
+  if (msAbs >= h) {
+    return Math.round(ms / h) + 'h';
+  }
+  if (msAbs >= m) {
+    return Math.round(ms / m) + 'm';
+  }
+  if (msAbs >= s) {
+    return Math.round(ms / s) + 's';
+  }
+  return ms + 'ms';
+}
+
+/**
+ * Long format for `ms`.
+ *
+ * @param {Number} ms
+ * @return {String}
+ * @api private
+ */
+
+function fmtLong(ms) {
+  var msAbs = Math.abs(ms);
+  if (msAbs >= d) {
+    return plural(ms, msAbs, d, 'day');
+  }
+  if (msAbs >= h) {
+    return plural(ms, msAbs, h, 'hour');
+  }
+  if (msAbs >= m) {
+    return plural(ms, msAbs, m, 'minute');
+  }
+  if (msAbs >= s) {
+    return plural(ms, msAbs, s, 'second');
+  }
+  return ms + ' ms';
+}
+
+/**
+ * Pluralization helper.
+ */
+
+function plural(ms, msAbs, n, name) {
+  var isPlural = msAbs >= n * 1.5;
+  return Math.round(ms / n) + ' ' + name + (isPlural ? 's' : '');
+}

pwa/node_modules/ms/license.md

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2020 Vercel, Inc.
+
+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/ms/package.json

@@ -0,0 +1,38 @@
+{
+  "name": "ms",
+  "version": "2.1.3",
+  "description": "Tiny millisecond conversion utility",
+  "repository": "vercel/ms",
+  "main": "./index",
+  "files": [
+    "index.js"
+  ],
+  "scripts": {
+    "precommit": "lint-staged",
+    "lint": "eslint lib/* bin/*",
+    "test": "mocha tests.js"
+  },
+  "eslintConfig": {
+    "extends": "eslint:recommended",
+    "env": {
+      "node": true,
+      "es6": true
+    }
+  },
+  "lint-staged": {
+    "*.js": [
+      "npm run lint",
+      "prettier --single-quote --write",
+      "git add"
+    ]
+  },
+  "license": "MIT",
+  "devDependencies": {
+    "eslint": "4.18.2",
+    "expect.js": "0.3.1",
+    "husky": "0.14.3",
+    "lint-staged": "5.0.0",
+    "mocha": "4.0.1",
+    "prettier": "2.0.5"
+  }
+}

pwa/node_modules/ms/readme.md

@@ -0,0 +1,59 @@
+# ms
+
+![CI](https://github.com/vercel/ms/workflows/CI/badge.svg)
+
+Use this package to easily convert various time formats to milliseconds.
+
+## Examples
+
+```js
+ms('2 days')  // 172800000
+ms('1d')      // 86400000
+ms('10h')     // 36000000
+ms('2.5 hrs') // 9000000
+ms('2h')      // 7200000
+ms('1m')      // 60000
+ms('5s')      // 5000
+ms('1y')      // 31557600000
+ms('100')     // 100
+ms('-3 days') // -259200000
+ms('-1h')     // -3600000
+ms('-200')    // -200
+```
+
+### Convert from Milliseconds
+
+```js
+ms(60000)             // "1m"
+ms(2 * 60000)         // "2m"
+ms(-3 * 60000)        // "-3m"
+ms(ms('10 hours'))    // "10h"
+```
+
+### Time Format Written-Out
+
+```js
+ms(60000, { long: true })             // "1 minute"
+ms(2 * 60000, { long: true })         // "2 minutes"
+ms(-3 * 60000, { long: true })        // "-3 minutes"
+ms(ms('10 hours'), { long: true })    // "10 hours"
+```
+
+## Features
+
+- Works both in [Node.js](https://nodejs.org) and in the browser
+- If a number is supplied to `ms`, a string with a unit is returned
+- If a string that contains the number is supplied, it returns it as a number (e.g.: it returns `100` for `'100'`)
+- If you pass a string with a number and a valid unit, the number of equivalent milliseconds is returned
+
+## Related Packages
+
+- [ms.macro](https://github.com/knpwrs/ms.macro) - Run `ms` as a macro at build-time.
+
+## Caught a Bug?
+
+1. [Fork](https://help.github.com/articles/fork-a-repo/) this repository to your own GitHub account and then [clone](https://help.github.com/articles/cloning-a-repository/) it to your local device
+2. Link the package to the global module directory: `npm link`
+3. Within the module you want to test your local development instance of ms, just link it to the dependencies: `npm link ms`. Instead of the default one from npm, Node.js will now use your clone of ms!
+
+As always, you can run the tests using: `npm test`