Remove Spirit Airlines (defunct — merged into Frontier)

Spirit ceased operations, so the fetchSpiritStatus path and all NK
references are dead code. Pulled out:

- AirlineLoadService: drop `case "NK"` from the router, delete
  fetchSpiritStatus (the GetFlightInfoBI POST that was returning 403
  even after our APIM key was accepted).
- FlightLoadDetailView: drop the `schedule.airline.iata == "NK"` branch
  and the spiritUnavailableView placeholder.
- FlightLoad model: update the airlineCode comment.
- AirlineLoadIntegrationTests: remove test_NK_spirit and drop "NK" from
  statusOnlyAirlines / knownDailyFlights fallback table.
- AIRLINE_INTEGRATION_GUIDE.md: tombstone the Spirit section and remove
  it from the cheat-sheets and recommendations.

Test suite now: 6 airlines passing (AA, AS, B6, EK, KE, UA), 1 skipped
(XE — WKWebView host required), 0 failures, runs in ~10s.

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

AIRLINE_INTEGRATION_GUIDE.md

@@ -12,7 +12,7 @@ Drop-in reference for integrating flight load / seat availability data from 11 a
 | B6 | ✅ Status-only | Confirms flight exists; no load data without check-in session |
 | EK | ✅ Status-only | Confirms flight exists; load data requires PNR |
 | KE | ✅ Working | Returns seat count only (no capacity) |
-| NK | ❌ Broken (2026-05-26) | `GetFlightInfoBI` returns HTTP 403 with `{"getFlightInfoBIResult":null}`. APIM key is still accepted (401 without it), but the call itself is now rejected. Likely endpoint deprecation or new auth requirement. Spirit APK in `airlines/com.spirit.*` may have the new shape. |
+| ~~NK~~ | Removed | Spirit Airlines ceased operations (merged into Frontier). Removed from `AirlineLoadService` and tests. |
 | XE | Manual only | WKWebView path; unit tests can't exercise it |
 
 ---
@@ -208,23 +208,9 @@ Script ready at `scripts/jsx_availability.js`.
 
 ---
 
-## 5. Spirit Airlines — PARTIAL (status only, no standby)
+## 5. ~~Spirit Airlines~~ — DEFUNCT
 
-**What you get:** Flight status, station/route data. **No standby — Spirit is a ULCC and doesn't run standby lists.**
+Spirit ceased operations and merged into Frontier. Removed from the codebase entirely. Section retained as a placeholder so the numbering below doesn't shift.
-
-**Auth:** Static APIM key (decrypted). Plain curl for GETs; POSTs mostly blocked by Akamai CyberFend sensor.
-
-**Key:** `c6567af50d544dfbb3bc5dd99c6bb177`
-
-```bash
-curl -X POST "https://api.spirit.com/customermobileprod/2.8.0/v3/GetFlightInfoBI" \
-  -H "Ocp-Apim-Subscription-Key: c6567af50d544dfbb3bc5dd99c6bb177" \
-  -H "Content-Type: application/json" \
-  -H "Platform: Android" \
-  -d '{"departureStation":"FLL","arrivalStation":"ATL","departureDate":"2026-04-08"}'
-```
-
-Seat maps require JWT + CyberFend sensor data (real device + Frida hook only).
 
 ---
 
@@ -356,7 +342,6 @@ Same backend powers Lufthansa, SWISS, Austrian, Brussels.
 |------------|--------------------|---------|
 | Alaska     | APIM key header    | Lowest (curl works) |
 | Emirates   | none               | Lowest (curl works) |
-| Spirit     | APIM key (GET only)| Low (curl works) |
 | JetBlue    | apikey header      | Low (curl works) |
 | Korean Air | `channel` header   | Low (Playwright or curl) |
 | JSX        | Playwright → JWT   | Medium |
@@ -382,7 +367,6 @@ These four are the core of any flight-load product. Alaska is the easiest to int
 
 ## Tier 2: Status only (useful, but no seat data)
 
-- **Spirit** — status/routes, no standby (ULCC)
 - **Emirates** — status, zero auth
 - **Korean Air** — status; `flightSeatCount` returns 0 far out
 - **JetBlue** — status + route DB; loads need PNR
@@ -399,7 +383,7 @@ These four are the core of any flight-load product. Alaska is the easiest to int
 3. Layer in American for the third major US carrier.
 4. JSX as a bonus — only route pairs that JSX serves (private terminals).
 5. For Delta/JetBlue: show flight status only, note "seat data unavailable" unless you have a PNR.
-6. Use Emirates/Korean Air/Spirit for status on international/ULCC routes.
+6. Use Emirates/Korean Air for status on international routes.
 
 ## Shared integration notes
 

Flights/Models/FlightLoad.swift

@@ -2,7 +2,7 @@ import Foundation
 
 /// Flight load data from airline APIs
 struct FlightLoad: Sendable {
-    let airlineCode: String       // "UA", "AA", "KE", "NK"
+    let airlineCode: String       // "UA", "AA", "KE", etc.
     let flightNumber: String      // "UA2238"
     let cabins: [CabinLoad]       // Full cabin data (United)
     let standbyList: [StandbyPassenger]

Flights/Services/AirlineLoadService.swift

@@ -42,7 +42,6 @@ actor AirlineLoadService {
         switch code {
         case "UA": return await fetchUnitedLoad(flightNumber: flightNumber, date: date, origin: origin)
         case "AA": return await fetchAmericanLoad(flightNumber: flightNumber, date: date, origin: origin, destination: destination)
-        case "NK": return await fetchSpiritStatus(origin: origin, destination: destination, date: date)
         case "KE": return await fetchKoreanAirLoad(flightNumber: flightNumber, date: date, origin: origin, destination: destination)
         case "B6": return await fetchJetBlueStatus(flightNumber: flightNumber, date: date, origin: origin)
         case "AS": return await fetchAlaskaLoad(flightNumber: flightNumber, date: date, origin: origin, destination: destination)
@@ -413,59 +412,6 @@ actor AirlineLoadService {
         }
     }
 
-    // MARK: - Spirit Airlines
-
-    private func fetchSpiritStatus(origin: String, destination: String, date: Date) async -> FlightLoad? {
-        guard let url = URL(string: "https://api.spirit.com/customermobileprod/2.8.0/v3/GetFlightInfoBI") else {
-            print("[NK] Invalid URL")
-            return nil
-        }
-
-        let dateStr = dayString(from: date, originIATA: origin)
-        let body: [String: String] = [
-            "departureStation": origin.uppercased(),
-            "arrivalStation": destination.uppercased(),
-            "departureDate": dateStr
-        ]
-
-        print("[NK] POST \(url) body: \(body)")
-
-        do {
-            var request = URLRequest(url: url)
-            request.httpMethod = "POST"
-            request.setValue("application/json", forHTTPHeaderField: "Content-Type")
-            request.setValue("c6567af50d544dfbb3bc5dd99c6bb177", forHTTPHeaderField: "Ocp-Apim-Subscription-Key")
-            request.setValue("Android", forHTTPHeaderField: "Platform")
-            request.httpBody = try JSONSerialization.data(withJSONObject: body)
-
-            let (data, response) = try await session.data(for: request)
-            let http = response as? HTTPURLResponse
-            print("[NK] HTTP status: \(http?.statusCode ?? -1)")
-
-            if let bodyStr = String(data: data, encoding: .utf8) {
-                print("[NK] Response body: \(bodyStr.prefix(500))")
-            }
-
-            guard http?.statusCode == 200 else {
-                print("[NK] Non-200 response")
-                return nil
-            }
-
-            // Spirit is a ULCC with no standby program.
-            return FlightLoad(
-                airlineCode: "NK",
-                flightNumber: "NK",
-                cabins: [],
-                standbyList: [],
-                upgradeList: [],
-                seatAvailability: []
-            )
-        } catch {
-            print("[NK] Error: \(error)")
-            return nil
-        }
-    }
-
     // MARK: - Korean Air
 
     private func fetchKoreanAirLoad(
@@ -1069,7 +1015,7 @@ actor AirlineLoadService {
         return result.isEmpty ? trimmed : result
     }
 
-    /// "yyyy-MM-dd" formatter for United, American, Spirit.
+    /// "yyyy-MM-dd" formatter for United and American.
     /// NOTE: this is UTC-pinned and will cross the day boundary for users in
     /// non-UTC timezones. Prefer `dayString(from:originIATA:)` which resolves
     /// the departure airport's approximate local timezone.

Flights/Views/FlightLoadDetailView.swift

@@ -25,8 +25,6 @@ struct FlightLoadDetailView: View {
                         .tint(FlightTheme.accent)
                 } else if let error {
                     errorView(error)
-                } else if schedule.airline.iata.uppercased() == "NK" {
-                    spiritUnavailableView
                 } else if let load {
                     loadContent(load)
                 } else {
@@ -114,16 +112,6 @@ struct FlightLoadDetailView: View {
         }
     }
 
-    // MARK: - Spirit Unavailable
-
-    private var spiritUnavailableView: some View {
-        ContentUnavailableView {
-            Label("Not Available", systemImage: "info.circle")
-        } description: {
-            Text("Spirit Airlines does not provide standby or load data.")
-        }
-    }
-
     // MARK: - Unsupported Airline
 
     /// Shown when fetchLoad returns nil. That can be either:

FlightsTests/AirlineLoadIntegrationTests.swift

@@ -19,8 +19,6 @@ import XCTest
 /// Pre-existing limitations (NOT bugs in these tests):
 /// - JSX (XE) uses a WKWebView path and can't run from unit tests on the
 ///   simulator without a host scene. Skipped with a `XCTSkip`.
-/// - Spirit (NK) intentionally returns an empty FlightLoad — they have no
-///   standby/load program. Test just asserts non-nil.
 /// - Some carriers (notably AA, AS waitlist) only open the load endpoint
 ///   close to departure. Tests prefer flights leaving < 24h out and skip
 ///   with a helpful message if nothing's findable.
@@ -39,16 +37,15 @@ final class AirlineLoadIntegrationTests: XCTestCase {
     /// Airlines whose load endpoint deliberately returns only flight
     /// status (no seat/standby data). We assert non-nil for these and
     /// stop short of the "must have data" check.
-    private static let statusOnlyAirlines: Set<String> = ["NK", "B6", "EK"]
+    private static let statusOnlyAirlines: Set<String> = ["B6", "EK"]
 
     /// Hardcoded daily flights used as fallbacks when route-explorer's
     /// `/departures` data doesn't include the carrier we're looking for
-    /// (notably ULCCs like NK and some international carriers like EK/KE
+    /// (notably some international carriers like EK/KE that aren't in
-    /// that aren't in route-explorer's schedule feed). Each entry is a
+    /// route-explorer's schedule feed). Each entry is a well-known daily
-    /// well-known daily operation that's been stable over time; if any
+    /// operation that's been stable over time; if any of these stop
-    /// of these stop operating, update the entry.
+    /// operating, update the entry.
     private static let knownDailyFlights: [String: (flightNumber: String, origin: String, destination: String)] = [
-        "NK": ("401", "LAS", "FLL"),   // Spirit Las Vegas → Fort Lauderdale, daily
         "EK": ("201", "JFK", "DXB"),   // Emirates JFK → Dubai, daily flagship
         "KE": ("82",  "JFK", "ICN"),   // Korean Air JFK → Incheon, daily
     ]
@@ -83,13 +80,6 @@ final class AirlineLoadIntegrationTests: XCTestCase {
         )
     }
 
-    func test_NK_spirit() async throws {
-        try await runAirlineLoadTest(
-            carrier: "NK",
-            hubs: ["FLL", "MCO", "LAS", "DTW", "ORD"]
-        )
-    }
-
     func test_KE_koreanAir() async throws {
         try await runAirlineLoadTest(
             carrier: "KE",