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/ajv/dist/vocabularies/code.d.ts

@@ -0,0 +1,17 @@
+import type { SchemaMap } from "../types";
+import type { SchemaCxt } from "../compile";
+import type { KeywordCxt } from "../compile/validate";
+import { CodeGen, Code, Name } from "../compile/codegen";
+export declare function checkReportMissingProp(cxt: KeywordCxt, prop: string): void;
+export declare function checkMissingProp({ gen, data, it: { opts } }: KeywordCxt, properties: string[], missing: Name): Code;
+export declare function reportMissingProp(cxt: KeywordCxt, missing: Name): void;
+export declare function hasPropFunc(gen: CodeGen): Name;
+export declare function isOwnProperty(gen: CodeGen, data: Name, property: Name | string): Code;
+export declare function propertyInData(gen: CodeGen, data: Name, property: Name | string, ownProperties?: boolean): Code;
+export declare function noPropertyInData(gen: CodeGen, data: Name, property: Name | string, ownProperties?: boolean): Code;
+export declare function allSchemaProperties(schemaMap?: SchemaMap): string[];
+export declare function schemaProperties(it: SchemaCxt, schemaMap: SchemaMap): string[];
+export declare function callValidateCode({ schemaCode, data, it: { gen, topSchemaRef, schemaPath, errorPath }, it }: KeywordCxt, func: Code, context: Code, passSchema?: boolean): Code;
+export declare function usePattern({ gen, it: { opts } }: KeywordCxt, pattern: string): Name;
+export declare function validateArray(cxt: KeywordCxt): Name;
+export declare function validateUnion(cxt: KeywordCxt): void;