fix(app): resolve all Pylance and Ruff errors

Update echo-tutor features and UI

Fix microphone hanging with VAD and prevent server sleep

Fix chat startup latency, personalize greeting, stabilize auto/hands-free flow

feat: Arabic UI toggle, RTL CSS, IELTS/TOEFL scenarios, Cairo font, bilingual states

feat: Arabic UI & RTL support, IELTS/TOEFL scenarios, streak logic, improved toasts, avatar char selector

feat: Arabic UI + RTL support, 8-language support (ar/tr/it/pt), animated avatar characters, IELTS/TOEFL scenarios, improved toast notifications, streak tracking, Cairo font

feat: add /story/image endpoint with Unsplash→Pexels→Pollinations fallback + image API keys in config

feat: add Stories + Flashcards + Progress screens with bottom nav

Fix auth proxy IP forwarding, improve rate limiting, and polish UI/mobile behavior

Improve mobile web UX, STT/TTS reliability, service worker caching, and Android APK landing flow

Update PWA configuration to support PWA installation and TWA app generation

Fix: onboarding always scrollable, never cut off on mobile

Responsive onboarding: mobile grid/flex fixes

feat(ui): premium bilingual landing page and animated character

feat(ui): add pre-login landing and temporary guest trial flow

feat: split auth into dedicated pages and enable flask auth routes

feat: replace auth module with updated Nova bridge and wire auth UI

chore: apply latest formatting and UI script/html updates

feat: add full interactive settings hub for UI/UX behavior

feat: add STT modes, voice profiles, and robust whisper diagnostics

Fix desktop responsive layout and add Whisper STT fallback

Fix mobile layout responsiveness

Update tutor app UI, exercises, and dependencies

Update space