[Enhancement] Implement Comprehensive Debugging System (Ruchy-Debug-V2)

[noahgift]

Objective

Replace the limited ruchydbg macro with a comprehensive debugging system for the Ruchy runtime. The current system lacks granular control, structured output, and integration with standard tools.

Features to Implement

1. Structured Logging & Tracing

• Replace println! based debugging with tracing crate.
• Implement RUCHY_LOG levels (error, warn, info, debug, trace).
• Add structured fields (span, file, line) to log events.

2. Interactive Debugger (CLI)

• Implement a REPL-based debugger (ruchy debug script.ruchy).
• Commands: step, next, continue, break <line>, inspect <var>.
• Stack trace printing with source code context.

3. AST & Bytecode Inspection

• Add --dump-ast flag to visualize the parsed AST (JSON/Graphviz).
• Add --dump-bytecode flag to see the compiled instructions before execution.
• Source mapping (Span -> Line/Col) for accurate error reporting.

4. Remote Debugging (DAP) - Future

• Lay groundwork for Debug Adapter Protocol (DAP) to support VS Code integration.

Implementation Plan

1. Add tracing and tracing-subscriber dependencies.
2. Refactor ruchydbg! to use tracing::debug!.
3. Implement DebugContext struct to track breakpoints and execution state.
4. Create debug_cmd.rs for the interactive CLI.
5. Enhance Parser and Compiler to support inspection flags.

Success Criteria

• Developers can trace execution flow without recompiling.
• Users can inspect variable state at runtime.
• AST/Bytecode dumps are available for compiler debugging.