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/ejs/usage.txt

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+EJS Embedded JavaScript templates
+{Usage}: ejs [options ...] template-file [data variables ...]
+
+{Options}:
+  -o,     --output-file FILE            Write the rendered output to FILE rather than stdout.
+  -f,     --data-file FILE              Must be JSON-formatted. Use parsed input from FILE as data for rendering.
+  -i,     --data-input STRING           Must be JSON-formatted and URI-encoded. Use parsed input from STRING as data for rendering.
+  -m,     --delimiter CHARACTER         Use CHARACTER with angle brackets for open/close (defaults to %).
+  -p,     --open-delimiter CHARACTER    Use CHARACTER instead of left angle bracket to open.
+  -c,     --close-delimiter CHARACTER   Use CHARACTER instead of right angle bracket to close.
+  -s,     --strict                      When set to `true`, generated function is in strict mode
+  -n      --no-with                     Use 'locals' object for vars rather than using `with` (implies --strict).
+  -l      --locals-name                 Name to use for the object storing local variables when not using `with`.
+  -w      --rm-whitespace               Remove all safe-to-remove whitespace, including leading and trailing whitespace.
+  -d      --debug                       Outputs generated function body
+  -h,     --help                        Display this help message.
+  -V/v,   --version                     Display the EJS version.
+
+{Examples}:
+  ejs -m $ ./test/fixtures/user.ejs -f ./user_data.json
+  ejs -m $ ./test/fixtures/user.ejs name=Lerxst
+  ejs -p [ -c ] ./template_file.ejs -o ./output.html
+  ejs -n -l _ ./some_template.ejs -f ./data_file.json
+  ejs -w ./template_with_whitspace.ejs -o ./output_file.html