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/lodash/_baseIntersection.js

@@ -0,0 +1,74 @@
+var SetCache = require('./_SetCache'),
+    arrayIncludes = require('./_arrayIncludes'),
+    arrayIncludesWith = require('./_arrayIncludesWith'),
+    arrayMap = require('./_arrayMap'),
+    baseUnary = require('./_baseUnary'),
+    cacheHas = require('./_cacheHas');
+
+/* Built-in method references for those with the same name as other `lodash` methods. */
+var nativeMin = Math.min;
+
+/**
+ * The base implementation of methods like `_.intersection`, without support
+ * for iteratee shorthands, that accepts an array of arrays to inspect.
+ *
+ * @private
+ * @param {Array} arrays The arrays to inspect.
+ * @param {Function} [iteratee] The iteratee invoked per element.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns the new array of shared values.
+ */
+function baseIntersection(arrays, iteratee, comparator) {
+  var includes = comparator ? arrayIncludesWith : arrayIncludes,
+      length = arrays[0].length,
+      othLength = arrays.length,
+      othIndex = othLength,
+      caches = Array(othLength),
+      maxLength = Infinity,
+      result = [];
+
+  while (othIndex--) {
+    var array = arrays[othIndex];
+    if (othIndex && iteratee) {
+      array = arrayMap(array, baseUnary(iteratee));
+    }
+    maxLength = nativeMin(array.length, maxLength);
+    caches[othIndex] = !comparator && (iteratee || (length >= 120 && array.length >= 120))
+      ? new SetCache(othIndex && array)
+      : undefined;
+  }
+  array = arrays[0];
+
+  var index = -1,
+      seen = caches[0];
+
+  outer:
+  while (++index < length && result.length < maxLength) {
+    var value = array[index],
+        computed = iteratee ? iteratee(value) : value;
+
+    value = (comparator || value !== 0) ? value : 0;
+    if (!(seen
+          ? cacheHas(seen, computed)
+          : includes(result, computed, comparator)
+        )) {
+      othIndex = othLength;
+      while (--othIndex) {
+        var cache = caches[othIndex];
+        if (!(cache
+              ? cacheHas(cache, computed)
+              : includes(arrays[othIndex], computed, comparator))
+            ) {
+          continue outer;
+        }
+      }
+      if (seen) {
+        seen.push(computed);
+      }
+      result.push(value);
+    }
+  }
+  return result;
+}
+
+module.exports = baseIntersection;