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/ejs/jakefile.js

@@ -0,0 +1,88 @@
+var fs = require('fs');
+var path = require('path');
+var execSync = require('child_process').execSync;
+var exec = function (cmd) {
+  execSync(cmd, {stdio: 'inherit'});
+};
+
+/* global jake, task, desc, publishTask */
+
+task('build', ['lint', 'clean', 'browserify', 'minify'], function () {
+  console.log('Build completed.');
+});
+
+desc('Cleans browerified/minified files and package files');
+task('clean', ['clobber'], function () {
+  jake.rmRf('./ejs.js');
+  jake.rmRf('./ejs.min.js');
+  console.log('Cleaned up compiled files.');
+});
+
+desc('Lints the source code');
+task('lint', ['clean'], function () {
+  var epath = path.join('./node_modules/.bin/eslint');
+  exec(epath+' "**/*.js"');
+  console.log('Linting completed.');
+});
+
+task('browserify', function () {
+  var epath = path.join('./node_modules/browserify/bin/cmd.js');
+  exec(epath+' --standalone ejs lib/ejs.js > ejs.js');
+  console.log('Browserification completed.');
+});
+
+task('minify', function () {
+  var epath = path.join('./node_modules/uglify-js/bin/uglifyjs');
+  exec(epath+' ejs.js > ejs.min.js');
+  console.log('Minification completed.');
+});
+
+desc('Generates the EJS API docs for the public API');
+task('doc', function () {
+  jake.rmRf('out');
+  var epath = path.join('./node_modules/.bin/jsdoc');
+  exec(epath+' --verbose -c jsdoc.json lib/* docs/jsdoc/*');
+  console.log('Documentation generated in ./out.');
+});
+
+desc('Generates the EJS API docs for the public and private API');
+task('devdoc', function () {
+  jake.rmRf('out');
+  var epath = path.join('./node_modules/.bin/jsdoc');
+  exec(epath+' --verbose -p -c jsdoc.json lib/* docs/jsdoc/*');
+  console.log('Documentation generated in ./out.');
+});
+
+desc('Publishes the EJS API docs');
+task('docPublish', ['doc'], function () {
+  fs.writeFileSync('out/CNAME', 'api.ejs.co');
+  console.log('Pushing docs to gh-pages...');
+  var epath = path.join('./node_modules/.bin/git-directory-deploy');
+  exec(epath+' --directory out/');
+  console.log('Docs published to gh-pages.');
+});
+
+desc('Runs the EJS test suite');
+task('test', ['lint'], function () {
+  exec(path.join('./node_modules/.bin/mocha --u tdd'));
+});
+
+publishTask('ejs', ['build'], function () {
+  this.packageFiles.include([
+    'jakefile.js',
+    'README.md',
+    'LICENSE',
+    'package.json',
+    'ejs.js',
+    'ejs.min.js',
+    'lib/**',
+    'bin/**',
+    'usage.txt'
+  ]);
+});
+
+jake.Task.publish.on('complete', function () {
+  console.log('Updating hosted docs...');
+  console.log('If this fails, run jake docPublish to re-try.');
+  jake.Task.docPublish.invoke();
+});