feat: Implement core functionality for DTC C/C++ IDE

- Added ProjectManager class to handle project operations including opening, closing, building, and running projects.
- Introduced SyntaxHighlighter class for syntax highlighting in C and C++ files.
- Developed TerminalWidget for command execution and output display.
- Created TextEditor with line numbering and auto-indentation features.
- Established main application entry point in main.cpp.
- Designed UI layout for MainWindow using Qt Designer.

create-sample-project.sh

@@ -0,0 +1,206 @@
+#!/bin/bash
+
+echo "🎯 Creating C++ sample project for testing DTC IDE..."
+
+# Create sample project directory
+mkdir -p /Users/dothanh1110/DTC/sample-cpp-project
+
+cd /Users/dothanh1110/DTC/sample-cpp-project
+
+# Create CMakeLists.txt
+cat > CMakeLists.txt << 'EOF'
+cmake_minimum_required(VERSION 3.20)
+project(SampleApp VERSION 1.0.0 LANGUAGES CXX)
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+# Add executable
+add_executable(sample-app
+    src/main.cpp
+    src/Calculator.cpp
+)
+
+# Include directories
+target_include_directories(sample-app PRIVATE include)
+
+# Install
+install(TARGETS sample-app DESTINATION bin)
+EOF
+
+# Create directories
+mkdir -p src include
+
+# Create main.cpp
+cat > src/main.cpp << 'EOF'
+#include <iostream>
+#include <string>
+#include "Calculator.h"
+
+int main() {
+    std::cout << "🧮 Welcome to Sample Calculator!" << std::endl;
+    
+    Calculator calc;
+    
+    // Test basic operations
+    std::cout << "Testing basic operations:" << std::endl;
+    std::cout << "5 + 3 = " << calc.add(5, 3) << std::endl;
+    std::cout << "10 - 4 = " << calc.subtract(10, 4) << std::endl;
+    std::cout << "6 * 7 = " << calc.multiply(6, 7) << std::endl;
+    std::cout << "15 / 3 = " << calc.divide(15, 3) << std::endl;
+    
+    // Interactive mode
+    std::cout << "\n📱 Interactive Calculator (type 'quit' to exit):" << std::endl;
+    
+    double a, b;
+    std::string operation;
+    
+    while (true) {
+        std::cout << "Enter operation (add/sub/mul/div) or 'quit': ";
+        std::cin >> operation;
+        
+        if (operation == "quit") {
+            break;
+        }
+        
+        std::cout << "Enter first number: ";
+        std::cin >> a;
+        std::cout << "Enter second number: ";
+        std::cin >> b;
+        
+        if (operation == "add") {
+            std::cout << "Result: " << calc.add(a, b) << std::endl;
+        } else if (operation == "sub") {
+            std::cout << "Result: " << calc.subtract(a, b) << std::endl;
+        } else if (operation == "mul") {
+            std::cout << "Result: " << calc.multiply(a, b) << std::endl;
+        } else if (operation == "div") {
+            std::cout << "Result: " << calc.divide(a, b) << std::endl;
+        } else {
+            std::cout << "Unknown operation!" << std::endl;
+        }
+        
+        std::cout << std::endl;
+    }
+    
+    std::cout << "👋 Goodbye!" << std::endl;
+    return 0;
+}
+EOF
+
+# Create Calculator.h
+cat > include/Calculator.h << 'EOF'
+#pragma once
+
+/**
+ * @brief Simple Calculator class for basic arithmetic operations
+ */
+class Calculator {
+public:
+    /**
+     * @brief Add two numbers
+     * @param a First number
+     * @param b Second number
+     * @return Sum of a and b
+     */
+    double add(double a, double b);
+    
+    /**
+     * @brief Subtract two numbers
+     * @param a First number
+     * @param b Second number
+     * @return Difference of a and b
+     */
+    double subtract(double a, double b);
+    
+    /**
+     * @brief Multiply two numbers
+     * @param a First number
+     * @param b Second number
+     * @return Product of a and b
+     */
+    double multiply(double a, double b);
+    
+    /**
+     * @brief Divide two numbers
+     * @param a Dividend
+     * @param b Divisor
+     * @return Quotient of a and b
+     * @throws std::invalid_argument if b is zero
+     */
+    double divide(double a, double b);
+    
+private:
+    static constexpr double EPSILON = 1e-9;
+};
+EOF
+
+# Create Calculator.cpp
+cat > src/Calculator.cpp << 'EOF'
+#include "Calculator.h"
+#include <stdexcept>
+#include <cmath>
+
+double Calculator::add(double a, double b) {
+    return a + b;
+}
+
+double Calculator::subtract(double a, double b) {
+    return a - b;
+}
+
+double Calculator::multiply(double a, double b) {
+    return a * b;
+}
+
+double Calculator::divide(double a, double b) {
+    if (std::abs(b) < EPSILON) {
+        throw std::invalid_argument("Division by zero is not allowed!");
+    }
+    return a / b;
+}
+EOF
+
+# Create README.md
+cat > README.md << 'EOF'
+# Sample C++ Calculator Project
+
+This is a sample C++ project for testing the DTC C/C++ IDE.
+
+## Features
+- Basic arithmetic operations (add, subtract, multiply, divide)
+- Interactive calculator mode
+- Error handling for division by zero
+- Modern C++20 features
+
+## Building
+
+```bash
+mkdir build && cd build
+cmake ..
+make
+```
+
+## Running
+
+```bash
+./sample-app
+```
+
+## Testing in DTC IDE
+
+1. Open DTC C/C++ IDE
+2. File → Open Project
+3. Select this directory
+4. Use Cmd+B to build
+5. Use Cmd+R to run
+EOF
+
+echo "✅ Sample C++ project created at: /Users/dothanh1110/DTC/sample-cpp-project"
+echo ""
+echo "📖 To test with DTC IDE:"
+echo "   1. Open the IDE: cd /Users/dothanh1110/DTC/ide-cpp && ./run.sh"
+echo "   2. File → Open Project"
+echo "   3. Select: /Users/dothanh1110/DTC/sample-cpp-project"
+echo "   4. Build: Cmd+B"
+echo "   5. Run: Cmd+R"