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/@vitest/utils/dist/source-map.d.ts

@@ -0,0 +1,117 @@
+import { ErrorWithDiff, ParsedStack } from './types.js';
+
+type GeneratedColumn = number;
+type SourcesIndex = number;
+type SourceLine = number;
+type SourceColumn = number;
+type NamesIndex = number;
+type SourceMapSegment = [GeneratedColumn] | [GeneratedColumn, SourcesIndex, SourceLine, SourceColumn] | [GeneratedColumn, SourcesIndex, SourceLine, SourceColumn, NamesIndex];
+
+interface SourceMapV3 {
+    file?: string | null;
+    names: string[];
+    sourceRoot?: string;
+    sources: (string | null)[];
+    sourcesContent?: (string | null)[];
+    version: 3;
+    ignoreList?: number[];
+}
+interface EncodedSourceMap extends SourceMapV3 {
+    mappings: string;
+}
+interface DecodedSourceMap extends SourceMapV3 {
+    mappings: SourceMapSegment[][];
+}
+type OriginalMapping = {
+    source: string | null;
+    line: number;
+    column: number;
+    name: string | null;
+};
+type InvalidOriginalMapping = {
+    source: null;
+    line: null;
+    column: null;
+    name: null;
+};
+type GeneratedMapping = {
+    line: number;
+    column: number;
+};
+type InvalidGeneratedMapping = {
+    line: null;
+    column: null;
+};
+type Bias = typeof GREATEST_LOWER_BOUND | typeof LEAST_UPPER_BOUND;
+type XInput = {
+    x_google_ignoreList?: SourceMapV3['ignoreList'];
+};
+type EncodedSourceMapXInput = EncodedSourceMap & XInput;
+type DecodedSourceMapXInput = DecodedSourceMap & XInput;
+type SourceMapInput = string | EncodedSourceMapXInput | DecodedSourceMapXInput | TraceMap;
+type Needle = {
+    line: number;
+    column: number;
+    bias?: Bias;
+};
+type SourceNeedle = {
+    source: string;
+    line: number;
+    column: number;
+    bias?: Bias;
+};
+declare abstract class SourceMap {
+    version: SourceMapV3['version'];
+    file: SourceMapV3['file'];
+    names: SourceMapV3['names'];
+    sourceRoot: SourceMapV3['sourceRoot'];
+    sources: SourceMapV3['sources'];
+    sourcesContent: SourceMapV3['sourcesContent'];
+    resolvedSources: SourceMapV3['sources'];
+    ignoreList: SourceMapV3['ignoreList'];
+}
+
+declare const LEAST_UPPER_BOUND = -1;
+declare const GREATEST_LOWER_BOUND = 1;
+
+declare class TraceMap implements SourceMap {
+    version: SourceMapV3['version'];
+    file: SourceMapV3['file'];
+    names: SourceMapV3['names'];
+    sourceRoot: SourceMapV3['sourceRoot'];
+    sources: SourceMapV3['sources'];
+    sourcesContent: SourceMapV3['sourcesContent'];
+    ignoreList: SourceMapV3['ignoreList'];
+    resolvedSources: string[];
+    private _encoded;
+    private _decoded;
+    private _decodedMemo;
+    private _bySources;
+    private _bySourceMemos;
+    constructor(map: SourceMapInput, mapUrl?: string | null);
+}
+/**
+ * A higher-level API to find the source/line/column associated with a generated line/column
+ * (think, from a stack trace). Line is 1-based, but column is 0-based, due to legacy behavior in
+ * `source-map` library.
+ */
+declare function originalPositionFor(map: TraceMap, needle: Needle): OriginalMapping | InvalidOriginalMapping;
+/**
+ * Finds the generated line/column position of the provided source/line/column source position.
+ */
+declare function generatedPositionFor(map: TraceMap, needle: SourceNeedle): GeneratedMapping | InvalidGeneratedMapping;
+
+interface StackTraceParserOptions {
+    ignoreStackEntries?: (RegExp | string)[];
+    getSourceMap?: (file: string) => unknown;
+    getFileName?: (id: string) => string;
+    frameFilter?: (error: ErrorWithDiff, frame: ParsedStack) => boolean | void;
+}
+declare function parseSingleFFOrSafariStack(raw: string): ParsedStack | null;
+declare function parseSingleStack(raw: string): ParsedStack | null;
+declare function parseSingleV8Stack(raw: string): ParsedStack | null;
+declare function createStackString(stacks: ParsedStack[]): string;
+declare function parseStacktrace(stack: string, options?: StackTraceParserOptions): ParsedStack[];
+declare function parseErrorStacktrace(e: ErrorWithDiff, options?: StackTraceParserOptions): ParsedStack[];
+
+export { type SourceMapInput, type StackTraceParserOptions, TraceMap, createStackString, generatedPositionFor, originalPositionFor, parseErrorStacktrace, parseSingleFFOrSafariStack, parseSingleStack, parseSingleV8Stack, parseStacktrace };