Import ESP_UniClock (upstream 1189810)

Vendored from https://github.com/gpeter62/ESP_UniClock: the sketch
source, the web UI and the libraries the ESP8266 build needs, unpacked
from the bundled zips. Adds a PlatformIO project for the ESP-12. The
source is unchanged; local changes follow as separate commits.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

firmware/uniclock/lib/ESPAsyncWiFiManager/library.properties

@@ -0,0 +1,9 @@
+name=ESP Async WiFi Manager
+version=0.22
+author=alanswx
+maintainer=alanswx
+sentence=ESP8266 and ESP32 Async WiFi Connection manager with fallback web configuration portal
+paragraph=Library for configuring ESP8266 and ESP32 modules WiFi credentials at runtime.
+category=Communication
+url=https://github.com/alanswx/ESPAsyncWiFiManager.git
+architectures=esp8266,esp32