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/PubSubClient/keywords.txt

@@ -0,0 +1,36 @@
+#######################################
+# Syntax Coloring Map For PubSubClient
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+PubSubClient	KEYWORD1
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+connect 	KEYWORD2
+disconnect 	KEYWORD2
+publish 	KEYWORD2
+publish_P 	KEYWORD2
+beginPublish 	KEYWORD2
+endPublish 	KEYWORD2
+write	 	KEYWORD2
+subscribe 	KEYWORD2
+unsubscribe 	KEYWORD2
+loop 	KEYWORD2
+connected 	KEYWORD2
+setServer	KEYWORD2
+setCallback	KEYWORD2
+setClient	KEYWORD2
+setStream	KEYWORD2
+setKeepAlive 	KEYWORD2
+setBufferSize 	KEYWORD2
+setSocketTimeout 	KEYWORD2
+
+#######################################
+# Constants (LITERAL1)
+#######################################