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/Timezone/library.properties

@@ -0,0 +1,10 @@
+name=Timezone
+version=1.2.4
+author=Jack Christensen <jack.christensen@outlook.com>
+maintainer=Jack Christensen <jack.christensen@outlook.com>
+sentence=Arduino library to facilitate time zone conversions and automatic daylight saving (summer) time adjustments.
+paragraph=The primary aim of the Timezone library is to convert Universal Coordinated Time (UTC) to the correct local time, whether it is daylight saving time (a.k.a. summer time) or standard time.
+category=Timing
+url=https://github.com/JChristensen/Timezone
+architectures=avr
+depends=Time