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/randombytes/test.js

@@ -0,0 +1,81 @@
+var test = require('tape')
+var randomBytes = require('./')
+var MAX_BYTES = 65536
+var MAX_UINT32 = 4294967295
+
+test('sync', function (t) {
+  t.plan(9)
+  t.equals(randomBytes(0).length, 0, 'len: ' + 0)
+  t.equals(randomBytes(3).length, 3, 'len: ' + 3)
+  t.equals(randomBytes(30).length, 30, 'len: ' + 30)
+  t.equals(randomBytes(300).length, 300, 'len: ' + 300)
+  t.equals(randomBytes(17 + MAX_BYTES).length, 17 + MAX_BYTES, 'len: ' + 17 + MAX_BYTES)
+  t.equals(randomBytes(MAX_BYTES * 100).length, MAX_BYTES * 100, 'len: ' + MAX_BYTES * 100)
+  t.throws(function () {
+    randomBytes(MAX_UINT32 + 1)
+  })
+  t.throws(function () {
+    t.equals(randomBytes(-1))
+  })
+  t.throws(function () {
+    t.equals(randomBytes('hello'))
+  })
+})
+
+test('async', function (t) {
+  t.plan(9)
+
+  randomBytes(0, function (err, resp) {
+    if (err) throw err
+
+    t.equals(resp.length, 0, 'len: ' + 0)
+  })
+
+  randomBytes(3, function (err, resp) {
+    if (err) throw err
+
+    t.equals(resp.length, 3, 'len: ' + 3)
+  })
+
+  randomBytes(30, function (err, resp) {
+    if (err) throw err
+
+    t.equals(resp.length, 30, 'len: ' + 30)
+  })
+
+  randomBytes(300, function (err, resp) {
+    if (err) throw err
+
+    t.equals(resp.length, 300, 'len: ' + 300)
+  })
+
+  randomBytes(17 + MAX_BYTES, function (err, resp) {
+    if (err) throw err
+
+    t.equals(resp.length, 17 + MAX_BYTES, 'len: ' + 17 + MAX_BYTES)
+  })
+
+  randomBytes(MAX_BYTES * 100, function (err, resp) {
+    if (err) throw err
+
+    t.equals(resp.length, MAX_BYTES * 100, 'len: ' + MAX_BYTES * 100)
+  })
+
+  t.throws(function () {
+    randomBytes(MAX_UINT32 + 1, function () {
+      t.ok(false, 'should not get here')
+    })
+  })
+
+  t.throws(function () {
+    randomBytes(-1, function () {
+      t.ok(false, 'should not get here')
+    })
+  })
+
+  t.throws(function () {
+    randomBytes('hello', function () {
+      t.ok(false, 'should not get here')
+    })
+  })
+})