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/tests/Misc/weird_strcmp.hpp

@@ -0,0 +1,29 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2022, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson/Namespace.hpp>
+
+#include <string.h>  // strcmp, strncmp
+
+// Issue #1198: strcmp() implementation that returns a value larger than 8-bit
+
+namespace ARDUINOJSON_NAMESPACE {
+int strcmp(const char* a, const char* b) {
+  int result = ::strcmp(a, b);
+  if (result > 0)
+    return 2147483647;
+  if (result < 0)
+    return -214748364;
+  return 0;
+}
+
+int strncmp(const char* a, const char* b, size_t n) {
+  int result = ::strncmp(a, b, n);
+  if (result > 0)
+    return 2147483647;
+  if (result < 0)
+    return -214748364;
+  return 0;
+}
+}  // namespace ARDUINOJSON_NAMESPACE