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/JsonDeserializer/incomplete_input.cpp

@@ -0,0 +1,29 @@
+// ArduinoJson - https://arduinojson.org
+// Copyright © 2014-2022, Benoit BLANCHON
+// MIT License
+
+#define ARDUINOJSON_DECODE_UNICODE 1
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("Truncated JSON input") {
+  const char* testCases[] = {"\"hello", "\'hello", "'\\u", "'\\u00", "'\\u000",
+                             // false
+                             "f", "fa", "fal", "fals",
+                             // true
+                             "t", "tr", "tru",
+                             // null
+                             "n", "nu", "nul",
+                             // object
+                             "{", "{a", "{a:", "{a:1", "{a:1,", "{a:1,"};
+  const size_t testCount = sizeof(testCases) / sizeof(testCases[0]);
+
+  DynamicJsonDocument doc(4096);
+
+  for (size_t i = 0; i < testCount; i++) {
+    const char* input = testCases[i];
+    CAPTURE(input);
+    REQUIRE(deserializeJson(doc, input) ==
+            DeserializationError::IncompleteInput);
+  }
+}