Ports the ESP32 Wi-Fi emulation (esp32c3_wifi, esp32_wifi_ap, esp32_wlan_*)
from the lcgamboa/PICSimLab QEMU fork and integrates it behind the
esp32c3_wifi NIC model, plus the supporting radio peripherals
(ANA/PHYA/FE/PWR manager).
- Exposes an open SSID 'qemu' bridged to the host via QEMU user-mode NAT
(libslirp, now enabled in the native build).
- Adds ESP-IDF 5.5 compatibility fixes: channel resolution from the
beacon DS Parameter Set IE / AP lookup, persistent SYSCON register
backing (phy_module_has_clock_bits), DMA inlink/outlink descriptor
mirroring, RX descriptor ring reset on item.next==0, and descriptor
ownership/length semantics.
- xteink-emu now starts with -nic user,model=esp32c3_wifi and synthesizes
an eFuse image with a fixed guest MAC.
Verified against a stock Arduino-ESP32 sketch: scans, finds 'qemu',
associates, gets DHCP 192.168.4.15, and completes an outbound TCP
connection. Unmodified CrossPoint firmware still needs the power-button
hold during boot (tracked separately).
