APALink for APFPV firmware

🔹 What's new?

1. Improved fallback logic:

   • Bitrate now drops faster when signal degrades
   • Smooth return to high bitrate when connection improves

2. New parameters in ap_alink.conf:

   • fallback_delay — sets the delay before activating fallback mode
   • recovery_dbm — threshold for returning to high bitrate

3. Performance optimisation:

   • Reduced CPU load during repeated Wi-Fi rescans
   • Faster connection startup after system reboot

4. New Wi-Fi card compatibility:

   • Added support for RTL8812BU and MT7921 chipsets

---

🔹 Recommended actions

• Update ap_alink to the latest version
• Check the new configuration file /etc/ap_alink.conf
• Restart the system after the update

Note: The old configuration is compatible, but updating ap_alink.conf is recommended to access new features.