v3.2.6 — Fix #50: itlwm download failure no longer blocks EFI build

Fixes #50 — itlwm.kext download failure blocked entire EFI build

Wi-Fi and Bluetooth kexts are now classified as optional. When GitHub is unreachable and no embedded fallback exists, the kext is removed from config.plist and the build continues. The system boots without Wi-Fi — the user can install the kext manually later.

Optional kexts (non-fatal on download failure):

• itlwm.kext (Intel Wi-Fi)
• AirportItlwm.kext (Intel Wi-Fi native)
• IntelBluetoothFirmware.kext
• BlueToolFixup.kext
• BrcmPatchRAM3.kext (Broadcom Bluetooth)
• AirportBrcmFixup.kext (Broadcom Wi-Fi)
• VoodooI2C.kext / VoodooI2CHID.kext (I2C trackpad — PS2 fallback still works)

Required kexts (still block build on failure):

• Lilu, VirtualSMC, WhateverGreen, AppleALC, SMCBatteryManager, ECEnabler, VoodooPS2Controller, and all other core kexts

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