🔧 Add dual-run configuration support for FastMCP migration

- Update generate_cursor_config.py to support both FastMCP and legacy servers
- Add --legacy flag to switch to old mcp_server_cli.py during transition
- Default to new FastMCP server (basecamp_fastmcp.py) - RECOMMENDED
- Auto-cleanup old server configs when switching
- Provide clear migration instructions and fallback options

Usage:
  python generate_cursor_config.py           # Use FastMCP (default)
  python generate_cursor_config.py --legacy  # Use legacy server

Following migration plan P-5: Safe dual-run deployment with easy rollback

generate_cursor_config.py

@@ -1,11 +1,13 @@
 #!/usr/bin/env python3
 """
 Generate the correct Cursor MCP configuration for this Basecamp MCP server.
+Supports both the new FastMCP server (default) and legacy server during migration.
 """
 
 import json
 import os
 import sys
+import argparse
 from pathlib import Path
 from dotenv import load_dotenv
 
@@ -24,12 +26,25 @@ def get_python_path():
     # Fallback to system Python
     return sys.executable
 
-def generate_config():
-    """Generate the MCP configuration for Cursor."""
+def generate_config(use_legacy=False):
+    """Generate the MCP configuration for Cursor.
+    
+    Args:
+        use_legacy: If True, use the legacy mcp_server_cli.py. If False, use new FastMCP server.
+    """
     project_root = get_project_root()
     python_path = get_python_path()
-    # Use absolute path to the MCP CLI script to avoid double-slash issues
-    script_path = os.path.join(project_root, "mcp_server_cli.py")
+    
+    if use_legacy:
+        # Use legacy server
+        script_path = os.path.join(project_root, "mcp_server_cli.py")
+        server_name = "basecamp-legacy"
+        print("🔄 Using LEGACY server (mcp_server_cli.py)")
+    else:
+        # Use new FastMCP server (default)
+        script_path = os.path.join(project_root, "basecamp_fastmcp.py")
+        server_name = "basecamp"
+        print("✨ Using NEW FastMCP server (basecamp_fastmcp.py) - RECOMMENDED")
 
     # Load .env file from project root to get BASECAMP_ACCOUNT_ID
     dotenv_path = os.path.join(project_root, ".env")
@@ -48,7 +63,7 @@ def generate_config():
 
     config = {
         "mcpServers": {
-            "basecamp": {
+            server_name: {
                 "command": python_path,
                 "args": [script_path],
                 "cwd": project_root,
@@ -57,7 +72,7 @@ def generate_config():
         }
     }
 
-    return config
+    return config, server_name
 
 def get_cursor_config_path():
     """Get the path to the Cursor MCP configuration file."""
@@ -72,7 +87,12 @@ def get_cursor_config_path():
 
 def main():
     """Main function."""
-    config = generate_config()
+    parser = argparse.ArgumentParser(description="Generate Cursor MCP configuration for Basecamp")
+    parser.add_argument("--legacy", action="store_true", 
+                       help="Use legacy mcp_server_cli.py instead of new FastMCP server")
+    args = parser.parse_args()
+
+    config, server_name = generate_config(use_legacy=args.legacy)
     config_path = get_cursor_config_path()
 
     print("🔧 Generated Cursor MCP Configuration:")
@@ -97,7 +117,15 @@ def main():
                 if "mcpServers" not in existing_config:
                     existing_config["mcpServers"] = {}
 
-                existing_config["mcpServers"]["basecamp"] = config["mcpServers"]["basecamp"]
+                existing_config["mcpServers"][server_name] = config["mcpServers"][server_name]
+
+                # Clean up old server entries if switching
+                if not args.legacy and "basecamp-legacy" in existing_config["mcpServers"]:
+                    print("🧹 Removing legacy server configuration...")
+                    del existing_config["mcpServers"]["basecamp-legacy"]
+                elif args.legacy and "basecamp" in existing_config["mcpServers"]:
+                    print("🧹 Removing new FastMCP server configuration...")
+                    del existing_config["mcpServers"]["basecamp"]
 
                 # Write back the updated config
                 config_path.parent.mkdir(parents=True, exist_ok=True)
@@ -128,10 +156,21 @@ def main():
             print("Configuration file not created.")
 
     print()
-    print("📋 Next steps:")
-    print("1. Make sure you've authenticated with Basecamp: python oauth_app.py")
-    print("2. Restart Cursor completely (quit and reopen)")
-    print("3. Check Cursor Settings → MCP for a green checkmark next to 'basecamp'")
+    if args.legacy:
+        print("📋 Next steps (Legacy Server):")
+        print("1. Make sure you've authenticated with Basecamp: python oauth_app.py")
+        print("2. Restart Cursor completely (quit and reopen)")
+        print("3. Check Cursor Settings → MCP for a green checkmark next to 'basecamp-legacy'")
+        print()
+        print("💡 TIP: Try the new FastMCP server by running without --legacy flag!")
+    else:
+        print("📋 Next steps (FastMCP Server):")
+        print("1. Make sure you've authenticated with Basecamp: python oauth_app.py")
+        print("2. Restart Cursor completely (quit and reopen)")
+        print("3. Check Cursor Settings → MCP for a green checkmark next to 'basecamp'")
+        print()
+        print("🚀 You're using the new FastMCP server - enjoy the improved performance!")
+        print("🔄 If you encounter issues, you can switch back with: python generate_cursor_config.py --legacy")
 
 if __name__ == "__main__":
     main()