feat: Add JPMS (Java Platform Module System) support

[gnodet]

Complete JPMS Migration with Java 24 Support

This PR implements comprehensive Java Platform Module System (JPMS) support for JLine 4.0, enabling modular applications while maintaining full backward compatibility.

🎯 Key Achievements

✅ JPMS Modules (12 modules)

• Core Infrastructure: terminal, reader, style, native
• Terminal Providers: terminal-jni (recommended), terminal-ffm (Java 22+), terminal-jna
• Extended Functionality: builtins, console, console-ui, jansi-core
• UI Components: curses (newly converted from automatic module)

❌ Automatic Modules (6 modules)

• terminal-jansi (deprecated - use JNI instead), groovy, remote-ssh, remote-telnet, demo, graal
• Remain automatic for compatibility with complex external dependencies

🚀 Java 24 Support

• FFM Provider: Foreign Function Memory API integration for best performance
• Native Access: Requires --enable-native-access=org.jline.terminal.ffm on module path
• Future-Ready: Prepared for modern JDK features

🔧 Technical Implementation

Strong Module Boundaries

module org.jline.terminal {
    requires java.base;
    requires java.logging;
    
    exports org.jline.terminal;
    exports org.jline.terminal.spi;
    
    uses org.jline.terminal.spi.TerminalProvider;
}

Service Provider Interface

• Automatic Discovery: Terminal providers discovered via SPI
• Priority Selection: JNI → FFM → JNA → Jansi (deprecated)
• Pluggable Architecture: Easy to add new terminal implementations

Recommended Provider Priority

1. 🥇 JNI (org.jline.terminal.jni) - No external dependencies, JDK 11+
2. 🥈 FFM (org.jline.terminal.ffm) - Best performance, JDK 22+
3. 🥉 JNA (org.jline.terminal.jna) - Alternative with JNA dependency
4. ❌ Jansi (org.jline.terminal.jansi) - Deprecated, use JNI instead

📋 Migration Guide

For New Modular Applications

module your.app {
    requires org.jline.terminal;
    requires org.jline.reader;
    requires org.jline.terminal.jni; // Recommended provider
    
    // Optional functionality
    requires org.jline.builtins;     // Built-in commands
    requires org.jline.curses;       // UI components
}

For Existing Applications

• Phase 1: Continue using jline uber-jar (automatic module)
• Phase 2: Switch to individual modules on classpath
• Phase 3: Convert application to JPMS module
• Phase 4: Optimize by removing unused modules

FFM Provider Setup (JDK 22+)

# ✅ CORRECT: JLine on module path
java --module-path jline-modules/ \
     --enable-native-access=org.jline.terminal.ffm \
     --module your.app/your.Main

# ❌ INCORRECT: JLine on classpath (flag won't work)
java -cp jline-jars:your-app.jar \
     --enable-native-access=org.jline.terminal.ffm \
     your.Main

🧪 Testing & Validation

• ✅ 1,300+ tests passing across all modules
• ✅ Full build success with mvn install
• ✅ Java 22+ compatibility verified
• ✅ Backward compatibility maintained
• ✅ Service provider discovery working correctly

📚 Documentation

New JPMS Guide

• Complete migration instructions from JLine 3.x
• Provider selection recommendations with rationale
• Module path requirements for FFM native access
• Troubleshooting section for common JPMS issues
• Best practices for different application types

Key Documentation Sections

• Module overview with JDK requirements
• Provider priority and selection guide
• Migration strategies for existing applications
• Troubleshooting common module path issues

🔄 Backward Compatibility

• ✅ Classpath applications continue to work unchanged
• ✅ Uber-bundles (jline, jansi) remain as automatic modules
• ✅ No breaking API changes in public interfaces
• ✅ Existing build configurations work without modification

🎁 Benefits

• 🔒 Strong Encapsulation: Internal APIs properly hidden from consumers
• ⚡ Better Performance: Module system enables JVM optimizations
• 🛡️ Enhanced Security: Reduced attack surface through encapsulation
• 🔍 Compile-time Safety: Explicit dependencies prevent runtime issues
• 🚀 Future-Ready: Foundation for modern Java features

🏗️ Architecture

graph TD
    A[Application] --> B[org.jline.reader]
    B --> C[org.jline.terminal]
    C --> D[Terminal Providers]
    D --> E[org.jline.terminal.jni]
    D --> F[org.jline.terminal.ffm]
    D --> G[org.jline.terminal.jna]
    B --> H[org.jline.builtins]
    A --> I[org.jline.curses]

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This migration establishes JLine as a modern, modular Java library ready for the next decade of Java development while ensuring existing applications continue to work seamlessly.