Virtual WiFi/Bluetooth environment + bridge-to-real mode

[Kinin-Code-Offical]

Goal: provide a simulated WiFi/BLE environment that can switch between:

• Virtual RF environment (APs/clients, loss, latency)
• Bridge-to-real host network/Bluetooth when desired

Acceptance:

• Works for both Arduino-class (when modeled) and RPi QEMU guest.
• Clean enable/disable; no always-on background cost.