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/JsonDocument/overflowed.cpp

@@ -0,0 +1,85 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2022, Benoit BLANCHON
+// MIT License
+
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("JsonDocument::overflowed()") {
+  SECTION("returns false on a fresh object") {
+    StaticJsonDocument<0> doc;
+    CHECK(doc.overflowed() == false);
+  }
+
+  SECTION("returns true after a failed insertion") {
+    StaticJsonDocument<0> doc;
+    doc.add(0);
+    CHECK(doc.overflowed() == true);
+  }
+
+  SECTION("returns false after successful insertion") {
+    StaticJsonDocument<JSON_ARRAY_SIZE(1)> doc;
+    doc.add(0);
+    CHECK(doc.overflowed() == false);
+  }
+
+  SECTION("returns true after a failed string copy") {
+    StaticJsonDocument<JSON_ARRAY_SIZE(1)> doc;
+    doc.add(std::string("example"));
+    CHECK(doc.overflowed() == true);
+  }
+
+  SECTION("returns false after a successful string copy") {
+    StaticJsonDocument<JSON_ARRAY_SIZE(1) + 8> doc;
+    doc.add(std::string("example"));
+    CHECK(doc.overflowed() == false);
+  }
+
+  SECTION("returns true after a failed member add") {
+    StaticJsonDocument<1> doc;
+    doc["example"] = true;
+    CHECK(doc.overflowed() == true);
+  }
+
+  SECTION("returns true after a failed deserialization") {
+    StaticJsonDocument<JSON_ARRAY_SIZE(1)> doc;
+    deserializeJson(doc, "[\"example\"]");
+    CHECK(doc.overflowed() == true);
+  }
+
+  SECTION("returns false after a successful deserialization") {
+    StaticJsonDocument<JSON_ARRAY_SIZE(1) + 8> doc;
+    deserializeJson(doc, "[\"example\"]");
+    CHECK(doc.overflowed() == false);
+  }
+
+  SECTION("returns false after clear()") {
+    StaticJsonDocument<0> doc;
+    doc.add(0);
+    doc.clear();
+    CHECK(doc.overflowed() == false);
+  }
+
+  SECTION("remains false after shrinkToFit()") {
+    DynamicJsonDocument doc(JSON_ARRAY_SIZE(1));
+    doc.add(0);
+    doc.shrinkToFit();
+    CHECK(doc.overflowed() == false);
+  }
+
+  SECTION("remains true after shrinkToFit()") {
+    DynamicJsonDocument doc(JSON_ARRAY_SIZE(1));
+    doc.add(0);
+    doc.add(0);
+    doc.shrinkToFit();
+    CHECK(doc.overflowed() == true);
+  }
+
+  SECTION("return false after garbageCollect()") {
+    DynamicJsonDocument doc(JSON_ARRAY_SIZE(1));
+    doc.add(0);
+    doc.add(0);
+    doc.garbageCollect();
+    CHECK(doc.overflowed() == false);
+  }
+}