fix: replace blocking NFC calls with proper coroutine/suspend APIs across all platforms

[codebutler]

iOS:

• Replace dispatch_semaphore bridging with suspendCancellableCoroutine in
  IosCardTransceiver, IosUltralightTechnology, IosVicinityTechnology, and
  IosFeliCaTagAdapter
• Replace runBlocking in IosNfcScanner with CoroutineScope(Dispatchers.IO)
  • GCD semaphore to avoid blocking GCD's worker queue thread
• Use DESFire native protocol directly instead of ISO 7816 SELECT, which
  requires AIDs registered in Info.plist (unregistered AIDs kill the session)
• Add NFCPollingISO15693 to NFC session polling options for NFC-V support
• Fix Xcode project paths from stale farebot-app/ to app/

Desktop:

• Make NfcReaderBackend.scanLoop() a suspend function, removing runBlocking
  from PN53xReaderBackend and PcscReaderBackend
• Wrap scan coroutine in try/finally to ensure _isScanning resets on cancel
• Share a single libusb context in PN533Device instead of per-call init/exit

WebUSB:

• Remove flush-on-open which left dangling transferIn promises that consumed
  subsequent device responses
• Increase transferIn buffer from 64 to 265 bytes for full PN533 frames
• Pass atrRetries to setMaxRetries so InListPassiveTarget self-resolves
  instead of relying on client-side abort (which WebUSB can't do)

DESFire:

• Handle COMMAND_ABORTED (0xCA) status code as access control exception