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>

api_docs/stafftraveler_captures/createLoadsRequests_AA2178_request.json

@@ -0,0 +1,31 @@
+[
+  {
+    "id": "a23d6f8379f5109eddeb5bbf78bdccc1",
+    "id_v2": "0d9d0702b203d224ace3e6eb94531dde",
+    "id_v3": "AA_2178_DFW_2026_04_22",
+    "airlineId": "AA",
+    "flightNumber": 2178,
+    "flightCode": "AA2178",
+    "departureAirportId": "DFW",
+    "arrivalAirportId": "LAS",
+    "departureTimeLocal": "2026-04-22T16:45:00-05:00",
+    "departureTimeUtc": "2026-04-22T21:45:00Z",
+    "arrivalTimeLocal": "2026-04-22T17:46:00-07:00",
+    "arrivalTimeUtc": "2026-04-23T00:46:00Z",
+    "flightEquipmentId": "32Q",
+    "durationMinutes": 181,
+    "isCargoFlight": false,
+    "airlineStCode": "st_AAL",
+    "departureAirportIata": "DFW",
+    "arrivalAirportIata": "LAS",
+    "flightEquipmentIata": "32Q",
+    "seatsTotal": 196,
+    "seatsByClass": {
+      "first": 0,
+      "business": 20,
+      "premiumEconomy": 0,
+      "economy": 176
+    },
+    "isPriorityRequest": false
+  }
+]