Refactor unpac-claude to use Claude SDK's MCP-based custom tool architecture
- Rewrite tools.ml to use Claude.Tool.create and Claude.Mcp_server
- Tools are now bundled into an in-process MCP server named "unpac"
- Custom tools accessible as mcp__unpac__<tool_name>
- Update agent.ml to register MCP server via Options.with_mcp_server
- Simplify handler: built-in tools handled by Claude CLI, custom tools via MCP
- Remove manual tool dispatch in on_tool_use handler
- Add on_tool_result handler for logging
This aligns with the Python Claude Agent SDK's approach where:
- Built-in tools (Read, Write, Bash, etc.) are handled by Claude CLI
- Custom tools are defined via MCP servers executed in-process
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>