Airline integration work: AirlineLoadService updates, docs, JSX scripts

- AirlineLoadService: pass airport DB for timezone-aware date strings,
  add browser-shaped headers for United, expand JetBlue/Alaska/Emirates
  signatures to take origin, log/parse fixes for Korean Air.
- FlightsApp: build AirlineLoadService with the airport DB and inject it.
- JSX: continued WebView-based fetcher work plus updated JSX_NOTES.
- Docs: add AIRLINE_INTEGRATION_GUIDE.md, drop the old AIRLINE_API_SPEC.md,
  add api_docs/ (StaffTraveler reverse-engineering captures + findings).
- Scripts: jsx_cdp_probe, jsx_live_monitor, jsx_swift_smoke for JSX
  protocol exploration.
- .gitignore: exclude airlines/ (local-only APK/IPA reverse-engineering).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -39,6 +39,7 @@ Pods/
 
 # APK files
 apps/
+airlines/
 
 # Claude
 .claude/