feat: Add Cursor MCP integration commands

[prosdev]

🎯 Overview

Add MCP integration commands for Cursor IDE to complement existing Claude Code integration. Currently we only support Claude Code via the claude CLI, but many users also use Cursor.

🚀 User Experience

# Default: Claude Code (existing behavior)
dev mcp install                    # Uses claude CLI
dev mcp list                       # Uses claude CLI  
dev mcp uninstall                  # Uses claude CLI

# New: Cursor support
dev mcp install --cursor           # Updates ~/.cursor/mcp.json
dev mcp list --cursor              # Shows Cursor MCP servers
dev mcp uninstall --cursor         # Removes from Cursor config

📋 Implementation

Cursor Config Format

Cursor expects MCP servers in ~/.cursor/mcp.json:

{
  "mcpServers": {
    "dev-agent-my-project": {
      "command": "dev",
      "args": ["mcp", "start"],
      "env": {
        "REPOSITORY_PATH": "/Users/user/workspace/my-project"
      }
    }
  }
}

Commands to Implement

dev mcp install --cursor

• Read existing ~/.cursor/mcp.json (create if missing)
• Generate unique server name (e.g., dev-agent-{basename})
• Add new MCP server entry
• Write back to file
• Show success message with restart instructions

dev mcp list --cursor

• Read ~/.cursor/mcp.json
• Display all dev-agent MCP servers
• Show repository paths and status

dev mcp uninstall --cursor

• Read ~/.cursor/mcp.json
• Remove dev-agent entry for current project
• Write back to file

📋 Tasks

• Add --cursor flag to existing MCP commands
• Implement Cursor config file reading/writing utilities
• Add server name generation (avoid conflicts)
• Handle missing config file gracefully
• Add error handling for file permissions
• Update help text to document both modes
• Add tests for Cursor config manipulation
• Update documentation

🧪 Testing

• Test config file creation when missing
• Test adding multiple projects
• Test removing specific projects
• Test handling malformed JSON
• Test file permission errors
• Integration test with actual Cursor setup

✅ Acceptance Criteria

• dev mcp install --cursor adds project to Cursor config
• dev mcp list --cursor shows Cursor MCP servers
• dev mcp uninstall --cursor removes project from Cursor config
• Existing Claude Code commands work unchanged (default behavior)
• Graceful error handling for missing files/permissions
• Clear instructions for restarting Cursor after changes

Priority: Medium
Estimate: 0.5 days