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/ESPAsyncWebServer/CMakeLists.txt

@@ -0,0 +1,17 @@
+set(COMPONENT_SRCDIRS
+    "src"
+)
+
+set(COMPONENT_ADD_INCLUDEDIRS
+    "src"
+)
+
+set(COMPONENT_REQUIRES
+    "arduino-esp32"
+    "AsyncTCP"
+)
+
+register_component()
+
+target_compile_definitions(${COMPONENT_TARGET} PUBLIC -DESP32)
+target_compile_options(${COMPONENT_TARGET} PRIVATE -fno-rtti)