Add PlatformIO project setup, local libraries, and PCB Gerber files

- Add platformio.ini for ESP32 DevKit (Arduino framework, espressif32 6.10.0)
- Vendor ArduinoJson, MPU6050_tockn, SCServo, Simple_FOC, and WebSockets
  so a fresh clone builds without downloading dependencies
- Add .gitignore rules for PlatformIO/IDE build artifacts
- Add controller PCB Gerber and drill files

3.Software/libraries/ArduinoJson/extras/tests/JsonVariant/nullptr.cpp

@@ -0,0 +1,43 @@
+#include <ArduinoJson.h>
+
+#include <catch.hpp>
+
+TEST_CASE("nullptr") {
+  DynamicJsonDocument doc(4096);
+  JsonVariant variant = doc.to<JsonVariant>();
+
+  SECTION("JsonVariant == nullptr") {
+    REQUIRE(variant == nullptr);
+    REQUIRE_FALSE(variant != nullptr);
+  }
+
+  SECTION("JsonVariant != nullptr") {
+    variant.set(42);
+
+    REQUIRE_FALSE(variant == nullptr);
+    REQUIRE(variant != nullptr);
+  }
+
+  SECTION("JsonVariant.set(nullptr)") {
+    variant.set(42);
+    variant.set(nullptr);
+
+    REQUIRE(variant.isNull());
+  }
+
+  SECTION("JsonVariant.set(nullptr) with unbound reference") {
+    JsonVariant unboundReference;
+
+    unboundReference.set(nullptr);
+
+    REQUIRE(variant.isNull());
+  }
+
+  SECTION("JsonVariant.is<nullptr_t>()") {
+    variant.set(42);
+    REQUIRE(variant.is<std::nullptr_t>() == false);
+
+    variant.clear();
+    REQUIRE(variant.is<std::nullptr_t>() == true);
+  }
+}