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/ArduinoJson/extras/scripts/wandbox/publish.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+
+set -eu
+
+ARDUINOJSON_H="$1"
+
+read_string() {
+	jq --slurp --raw-input '.' "$1"
+}
+
+compile() {
+	FILE_PATH="$(dirname $0)/$1.cpp"
+	cat >parameters.json <<END
+{
+  "code":$(read_string "$FILE_PATH"),
+  "codes": [{"file":"ArduinoJson.h","code":$(read_string "$ARDUINOJSON_H")}],
+  "options": "warning",
+  "compiler": "gcc-4.9.4",
+  "save": true
+}
+END
+	URL=$(curl -sS -H "Content-type: application/json" -d @parameters.json  https://wandbox.org/api/compile.json | jq --raw-output .url)
+	rm parameters.json
+	[ -n "$URL" ] && echo "$1: $URL"
+}
+
+compile "JsonGeneratorExample"
+compile "JsonParserExample"
+compile "MsgPackParserExample"