feat: prepare ParkTrack 1.4.0 parking search experience

[nawinds]

Summary

Introduces a map-first parking search flow with a draggable results panel, synchronized marker selection, non-modal parking details, and a real driving-route preview that keeps the map interactive and fits the complete route.

Changes

• draggable parking results list with explicit driving/walking context and live parking facts;
• relative result badges, localized long distance/duration formatting, availability colors, address and parking number titles, confidence, and direct route/external-map actions;
• synchronized native and Web marker emphasis, including dimmed parking geometry and counters;
• exact light/dark semantic parking palette, selected semantic outlines, thinner clusters, and single-tap cluster expansion;
• non-modal selected parking details with previous/next navigation, preserved results, scroll position, outside-tap collapse, and last-viewed highlighting;
• complete-route and selected-parking camera fitting with panel/safe-area/DPR insets;
• smooth Web geometry style updates without removing parking geometry;
• route cleanup after navigation, interactive route preview, destination pin, directional user marker, and responsive map controls;
• automatic parking availability refresh every 20 seconds;
• duplicate login language switcher removed;
• Russian and English localization;
• state, widget, formatting, marker, palette, clustering, deeplink, camera, route, refresh, and localization tests;
• version bump to 1.4.0+4 and release notes.

Testing

• flutter pub get — passed.
• dart run build_runner build --delete-conflicting-outputs — passed earlier in the release; no generated models changed in the latest fix.
• formatting check for every changed Dart file — passed, 0 changes.
• flutter analyze — passed, no issues found.
• flutter test — passed, 72 tests.
• flutter build web --release — passed; standard Web release bundle produced. Flutter also reports existing WebAssembly dry-run incompatibilities in flutter_secure_storage_web.
• flutter build apk --debug — passed; app-debug.apk produced.
• git diff --check — passed.
• dart format --output=none --set-exit-if-changed lib test — reports 9 pre-existing formatting differences in files outside this map/search change; unrelated rewrites were not committed.

Screenshots

• Android emulator smoke-tested in RU/light mode with local mock data: results panel, active/dimmed parking geometry, selected parking, responsive controls, back-to-results state, and last-viewed highlight were inspected.
• The login page was inspected and contains only one language switcher.
• Web, dark theme, and live-backend route-preview captures remain pending because the in-app browser was unavailable and the emulator had no live map/backend network session.

Known limitations

• Before merge, repeat the full live-backend flow on Android and Web in RU/EN and light/dark themes, especially external Yandex Maps launch and a real route preview.
• External Yandex Maps launch and fallback are covered by automated tests but were not exercised against an installed external application during this run.
• Parking addresses are resolved lazily from real zone coordinates and cached by Riverpod because the routing and zone API models do not currently include a display address.
• Repository-wide Dart formatting still contains 9 pre-existing differences outside this change.