fix: patch mint-mcp to resolve 'Cannot read properties of undefined' error & add MCP integration

[caapap]

What does this PR do?

This PR fixes a critical issue preventing the setup of the MCP (Model Context Protocol) server for Dify documentation. It also adds the necessary MCP configuration to docs.json.

Problem

When running npx mint-mcp add dify-6c0370d8, the installation fails with:

TypeError: Cannot read properties of undefined (reading 'name')

This is caused by a data structure mismatch in the deprecated mint-mcp package where it expects a nested tool.tool object, but the API returns a flat tool object.

Changes

1. docs.json: Added integrations.mcp configuration pointing to dify-6c0370d8.
2. patches/@mintlify+mcp+1.1.216.patch: Added a patch file using patch-package to fix the cli-config.js in @mintlify/mcp. This allows the tool to correctly parse the API response by handling both nested and flat tool object structures.
3. package.json: Added patch-package dependency and postinstall script to ensure the patch is applied automatically after npm install.

How to verify

1. Run npm install
2. Run npx mint-mcp add dify-6c0370d8
3. Verify that the installation succeeds and the MCP server is created at ~/.mcp/dify-6c0370d8

Technical Details

The fix modifies node_modules/@mintlify/mcp/bin/utils/cli-config.js in the initializeToolsFromConfig function to handle both data structures:

// Before: tool.tool.name (fails when tool is flat)
// After: (tool.tool || tool).name (handles both cases)