0.2.6

Release notes:

• Added a tool for obtaining cropped images of diagrams.
• Added a tool for generating graph network images from DOT code.
• Added tools for executing Astah scripts.
• Added a timeout to exclusive control during tool execution.
• Revised the tool for retrieving diagram layout anti-patterns.
• Revised the description of the MCP server guide.
• Revised the description of the diagram layout guide.
• Revised the contents of the README.
• Refactoring.