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/publish-particle-library.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+set -eu
+
+SOURCE_DIR="$(dirname "$0")/../.."
+WORK_DIR=$(mktemp -d)
+trap 'rm -rf "$WORK_DIR"' EXIT
+
+cp "$SOURCE_DIR/README.md" "$WORK_DIR/README.md"
+cp "$SOURCE_DIR/CHANGELOG.md" "$WORK_DIR/CHANGELOG.md"
+cp "$SOURCE_DIR/library.properties" "$WORK_DIR/library.properties"
+cp "$SOURCE_DIR/LICENSE.md" "$WORK_DIR/LICENSE.txt"
+cp -r "$SOURCE_DIR/src" "$WORK_DIR/"
+cp -r "$SOURCE_DIR/examples" "$WORK_DIR/"
+
+cd "$WORK_DIR"
+particle library upload
+particle library publish