Sprint 2 Step 1: base ASTNode class and Module concept

Adds the C++ editor stack foundation with ASTNode (id, conceptType, parent pointer, virtual dtor) and Module as the first concrete concept (name, targetLanguage). Header-only, compiles with C++20, test passes all assertions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

editor/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.20)
+project(WhetstoneEditor LANGUAGES CXX)
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+add_executable(step1_test tests/step1_test.cpp)
+target_include_directories(step1_test PRIVATE src)

editor/src/ast/ASTNode.h

@@ -0,0 +1,11 @@
+#pragma once
+#include <string>
+
+class ASTNode {
+public:
+    std::string id;
+    std::string conceptType;
+    ASTNode* parent = nullptr;
+
+    virtual ~ASTNode() = default;
+};

editor/src/ast/Module.h

@@ -0,0 +1,15 @@
+#pragma once
+#include "ASTNode.h"
+
+class Module : public ASTNode {
+public:
+    std::string name;
+    std::string targetLanguage;
+
+    Module() { conceptType = "Module"; }
+    Module(const std::string& id, const std::string& name, const std::string& lang)
+        : name(name), targetLanguage(lang) {
+        this->id = id;
+        this->conceptType = "Module";
+    }
+};

editor/tests/step1_test.cpp

@@ -0,0 +1,16 @@
+#include "../src/ast/Module.h"
+#include <cassert>
+#include <iostream>
+
+int main() {
+    Module m("SFE_M001", "SimpleFunctionExample", "python");
+
+    assert(m.id == "SFE_M001");
+    assert(m.name == "SimpleFunctionExample");
+    assert(m.targetLanguage == "python");
+    assert(m.conceptType == "Module");
+    assert(m.parent == nullptr);
+
+    std::cout << "Step 1: PASS" << std::endl;
+    return 0;
+}