* feat: add LOS workflow, global units, l10n cleanup, and mobile UI overflow fixes
Squashes prior PR commits into one changeset including: LOS map/service/tests, global metric/imperial unit system adoption, notification/BLE safety fixes, app-wide localization backfill/mojibake cleanup, and responsive UI title/overflow hardening.
* l10n: revert unrelated locale churn for LOS feature
* feat: keep LOS with app-wide unit settings
* fix: resolve post-merge app bar/import analyzer errors
* style: format screen files for CI
- Implement Community model for managing community data, including secret handling and PSK derivation.
- Create CommunityQrScannerScreen for scanning and joining communities via QR codes.
- Develop CommunityStore for persisting community data using SharedPreferences.
- Introduce QrCodeDisplay widget for displaying QR codes with customizable options.
- Add QrScannerWidget for reusable QR code scanning functionality with validation and controls.