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/parse.js

@@ -0,0 +1,141 @@
+'use strict';
+
+const { Node, Block } = require('./Node');
+const languages = require('./languages');
+
+const constants = {
+  ESCAPED_CHAR_REGEX: /^\\./,
+  QUOTED_STRING_REGEX: /^(['"`])((?:\\.|[^\1])+?)(\1)/,
+  NEWLINE_REGEX: /^\r*\n/
+};
+
+const parse = (input, options = {}) => {
+  if (typeof input !== 'string') {
+    throw new TypeError('Expected input to be a string');
+  }
+
+  const cst = new Block({ type: 'root', nodes: [] });
+  const stack = [cst];
+  const name = (options.language || 'javascript').toLowerCase();
+  const lang = languages[name];
+
+  if (typeof lang === 'undefined') {
+    throw new Error(`Language "${name}" is not supported by strip-comments`);
+  }
+
+  const { LINE_REGEX, BLOCK_OPEN_REGEX, BLOCK_CLOSE_REGEX } = lang;
+  let block = cst;
+  let remaining = input;
+  let token;
+  let prev;
+
+  const source = [BLOCK_OPEN_REGEX, BLOCK_CLOSE_REGEX].filter(Boolean);
+  let tripleQuotes = false;
+
+  if (source.every(regex => regex.source === '^"""')) {
+    tripleQuotes = true;
+  }
+
+  /**
+   * Helpers
+   */
+
+  const consume = (value = remaining[0] || '') => {
+    remaining = remaining.slice(value.length);
+    return value;
+  };
+
+  const scan = (regex, type = 'text') => {
+    const match = regex.exec(remaining);
+    if (match) {
+      consume(match[0]);
+      return { type, value: match[0], match };
+    }
+  };
+
+  const push = node => {
+    if (prev && prev.type === 'text' && node.type === 'text') {
+      prev.value += node.value;
+      return;
+    }
+    block.push(node);
+    if (node.nodes) {
+      stack.push(node);
+      block = node;
+    }
+    prev = node;
+  };
+
+  const pop = () => {
+    if (block.type === 'root') {
+      throw new SyntaxError('Unclosed block comment');
+    }
+    stack.pop();
+    block = stack[stack.length - 1];
+  };
+
+  /**
+   * Parse input string
+   */
+
+  while (remaining !== '') {
+    // escaped characters
+    if ((token = scan(constants.ESCAPED_CHAR_REGEX, 'text'))) {
+      push(new Node(token));
+      continue;
+    }
+
+    // quoted strings
+    if (block.type !== 'block' && (!prev || !/\w$/.test(prev.value)) && !(tripleQuotes && remaining.startsWith('"""'))) {
+      if ((token = scan(constants.QUOTED_STRING_REGEX, 'text'))) {
+        push(new Node(token));
+        continue;
+      }
+    }
+
+    // newlines
+    if ((token = scan(constants.NEWLINE_REGEX, 'newline'))) {
+      push(new Node(token));
+      continue;
+    }
+
+    // block comment open
+    if (BLOCK_OPEN_REGEX && options.block && !(tripleQuotes && block.type === 'block')) {
+      if ((token = scan(BLOCK_OPEN_REGEX, 'open'))) {
+        push(new Block({ type: 'block' }));
+        push(new Node(token));
+        continue;
+      }
+    }
+
+    // block comment close
+    if (BLOCK_CLOSE_REGEX && block.type === 'block' && options.block) {
+      if ((token = scan(BLOCK_CLOSE_REGEX, 'close'))) {
+        token.newline = token.match[1] || '';
+        push(new Node(token));
+        pop();
+        continue;
+      }
+    }
+
+    // line comment
+    if (LINE_REGEX && block.type !== 'block' && options.line) {
+      if ((token = scan(LINE_REGEX, 'line'))) {
+        push(new Node(token));
+        continue;
+      }
+    }
+
+    // Plain text (skip "C" since some languages use "C" to start comments)
+    if ((token = scan(/^[a-zABD-Z0-9\t ]+/, 'text'))) {
+      push(new Node(token));
+      continue;
+    }
+
+    push(new Node({ type: 'text', value: consume(remaining[0]) }));
+  }
+
+  return cst;
+};
+
+module.exports = parse;