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/object-inspect/.eslintrc

@@ -0,0 +1,53 @@
+{
+    "root": true,
+    "extends": "@ljharb",
+    "rules": {
+        "complexity": 0,
+        "func-style": [2, "declaration"],
+        "indent": [2, 4],
+        "max-lines": 1,
+        "max-lines-per-function": 1,
+        "max-params": [2, 4],
+        "max-statements": 0,
+        "max-statements-per-line": [2, { "max": 2 }],
+        "no-magic-numbers": 0,
+        "no-param-reassign": 1,
+        "strict": 0, // TODO
+    },
+    "overrides": [
+        {
+            "files": ["test/**", "test-*", "example/**"],
+            "extends": "@ljharb/eslint-config/tests",
+            "rules": {
+              "id-length": 0,
+            },
+        },
+        {
+            "files": ["example/**"],
+            "rules": {
+                "no-console": 0,
+            },
+        },
+        {
+            "files": ["test/browser/**"],
+            "env": {
+                "browser": true,
+            },
+        },
+        {
+            "files": ["test/bigint*"],
+            "rules": {
+                "new-cap": [2, { "capIsNewExceptions": ["BigInt"] }],
+            },
+        },
+        {
+            "files": "index.js",
+            "globals": {
+                "HTMLElement": false,
+            },
+            "rules": {
+                "no-use-before-define": 1,
+            },
+        },
+    ],
+}