feat: Add destroy_addon tool

[michaelmalave]

Description

This PR adds a new tool to the Heroku MCP Server that enables the removal of add-ons from Heroku applications. This functionality is essential for managing application resources and controlling costs by allowing users to remove unused or unnecessary add-ons.

Key Features

• New destroy_addon tool for removing add-ons from Heroku apps
• Comprehensive input validation with Zod schema
• Automatic confirmation handling for safe deletion
• Detailed error handling and user feedback
• Support for multiple add-on identifier types (UUID, name, or attachment name)

Technical Details

Implementation

• Added registerDestroyAddonTool function in src/tools/addons.ts
• Created destroyAddonOptionsSchema for input validation:
  • Required app parameter for target application
  • Required addon parameter supporting multiple identifier formats
• Integrated with Heroku CLI using addons:destroy command
• Added automatic confirmation to prevent accidental deletions
• Implemented standard error handling pattern

Error Handling

• Validates input parameters before execution
• Handles common error cases:
  • Non-existent add-ons
  • Permission issues
  • Invalid app names
• Returns clear error messages to users

Testing Instructions

Prerequisites

• Node.js 20 or higher
• Heroku CLI installed and authenticated
• Cursor

Testing

• Checkout this branch with git pull && git checkout tool-destroy_addon
• Ensure you're using the correct version of Node (>20.x)
• If you have the AI plugin installed, uninstall it: heroku plugins:uninstall @heroku/plugin-ai
• Run npm install && npm run build

Update and enable the mcp.json in Cursor.

{
  "mcpServers": {
    "heroku": {
      "command": "node --inspect Path/to/bin/heroku-mcp-server.mjs",
      "env": {
        "DEBUG": "true",
        "MCP_SERVER_REQUEST_TIMEOUT": 10000
      }
    }
  }
}

• Test the destruction of an addon (you may add one before this), providing correct required parameters. Both should succeed.
• Reinstall your Heroku CLI Plugin AI, if you uninstalled it: heroku plugins:install @heroku/plugin-ai

3. Error Cases
   • Try removing non-existent add-on
   • Attempt removal without proper permissions
   • Use invalid app name
   • Use invalid add-on identifier

Impact

• Enables complete add-on lifecycle management in MCP
• Improves resource management capabilities
• Reduces manual CLI operations
• Enhances automation possibilities for add-on management

Future Considerations

• Add batch deletion capability for multiple add-ons
• Implement dry-run mode for validation
• Add backup options before deletion for data-storing add-ons
• Consider adding force flag for skipping confirmations

Related Documentation

• Heroku Add-ons API
• Heroku CLI Add-ons Commands
• Zod Schema Validation