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/Numbers/parseNumber.cpp

@@ -0,0 +1,57 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2022, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.hpp>
+#include <catch.hpp>
+
+using namespace ARDUINOJSON_NAMESPACE;
+
+TEST_CASE("Test unsigned integer overflow") {
+  VariantData first, second;
+  first.init();
+  second.init();
+
+  // Avoids MSVC warning C4127 (conditional expression is constant)
+  size_t integerSize = sizeof(Integer);
+
+  if (integerSize == 8) {
+    parseNumber("18446744073709551615", first);
+    parseNumber("18446744073709551616", second);
+  } else {
+    parseNumber("4294967295", first);
+    parseNumber("4294967296", second);
+  }
+
+  REQUIRE(first.type() == uint8_t(VALUE_IS_UNSIGNED_INTEGER));
+  REQUIRE(second.type() == uint8_t(VALUE_IS_FLOAT));
+}
+
+TEST_CASE("Test signed integer overflow") {
+  VariantData first, second;
+  first.init();
+  second.init();
+
+  // Avoids MSVC warning C4127 (conditional expression is constant)
+  size_t integerSize = sizeof(Integer);
+
+  if (integerSize == 8) {
+    parseNumber("-9223372036854775808", first);
+    parseNumber("-9223372036854775809", second);
+  } else {
+    parseNumber("-2147483648", first);
+    parseNumber("-2147483649", second);
+  }
+
+  REQUIRE(first.type() == uint8_t(VALUE_IS_SIGNED_INTEGER));
+  REQUIRE(second.type() == uint8_t(VALUE_IS_FLOAT));
+}
+
+TEST_CASE("Invalid value") {
+  VariantData result;
+  result.init();
+
+  parseNumber("6a3", result);
+
+  REQUIRE(result.type() == uint8_t(VALUE_IS_NULL));
+}