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/strip-comments/lib/languages.js

@@ -0,0 +1,85 @@
+'use strict';
+
+exports.ada = { LINE_REGEX: /^--.*/ };
+exports.apl = { LINE_REGEX: /^⍝.*/ };
+
+exports.applescript = {
+  BLOCK_OPEN_REGEX: /^\(\*/,
+  BLOCK_CLOSE_REGEX: /^\*\)/
+};
+
+exports.csharp = {
+  LINE_REGEX: /^\/\/.*/
+};
+
+exports.haskell = {
+  BLOCK_OPEN_REGEX: /^\{-/,
+  BLOCK_CLOSE_REGEX: /^-\}/,
+  LINE_REGEX: /^--.*/
+};
+
+exports.html = {
+  BLOCK_OPEN_REGEX: /^\n*<!--(?!-?>)/,
+  BLOCK_CLOSE_REGEX: /^(?<!(?:<!-))-->/,
+  BLOCK_CLOSE_LOOSE_REGEX: /^(?<!(?:<!-))--\s*>/,
+  BLOCK_CLOSE_STRICT_NEWLINE_REGEX: /^(?<!(?:<!-))-->(\s*\n+|\n*)/,
+  BLOCK_CLOSE_STRICT_LOOSE_REGEX: /^(?<!(?:<!-))--\s*>(\s*\n+|\n*)/
+};
+
+exports.javascript = {
+  BLOCK_OPEN_REGEX: /^\/\*\*?(!?)/,
+  BLOCK_CLOSE_REGEX: /^\*\/(\n?)/,
+  LINE_REGEX: /^\/\/(!?).*/
+};
+
+exports.lua = {
+  BLOCK_OPEN_REGEX: /^--\[\[/,
+  BLOCK_CLOSE_REGEX: /^\]\]/,
+  LINE_REGEX: /^--.*/
+};
+
+exports.matlab = {
+  BLOCK_OPEN_REGEX: /^%{/,
+  BLOCK_CLOSE_REGEX: /^%}/,
+  LINE_REGEX: /^%.*/
+};
+
+exports.perl = {
+  LINE_REGEX: /^#.*/
+};
+
+exports.php = {
+  ...exports.javascript,
+  LINE_REGEX: /^(#|\/\/).*?(?=\?>|\n)/
+};
+
+exports.python = {
+  BLOCK_OPEN_REGEX: /^"""/,
+  BLOCK_CLOSE_REGEX: /^"""/,
+  LINE_REGEX: /^#.*/
+};
+
+exports.ruby = {
+  BLOCK_OPEN_REGEX: /^=begin/,
+  BLOCK_CLOSE_REGEX: /^=end/,
+  LINE_REGEX: /^#.*/
+};
+
+exports.shebang = exports.hashbang = {
+  LINE_REGEX: /^#!.*/
+};
+
+exports.c = exports.javascript;
+exports.csharp = exports.javascript;
+exports.css = exports.javascript;
+exports.java = exports.javascript;
+exports.js = exports.javascript;
+exports.less = exports.javascript;
+exports.pascal = exports.applescript;
+exports.ocaml = exports.applescript;
+exports.sass = exports.javascript;
+exports.sql = exports.ada;
+exports.swift = exports.javascript;
+exports.ts = exports.javascript;
+exports.typscript = exports.javascript;
+exports.xml = exports.html;