feat(mcp): enhance MCP installation with status tracking and custom configs

- Add /mcp-servers/ to .gitignore for MCP server installations
- Extend mcp_installations table with status, logs, and validation fields
- Refactor MCP install route to support custom configs, enable logs, and async installation
- Improve MCPSyncService with promise-based syncing to prevent concurrent operations

This update improves MCP management by adding robust installation tracking, custom configuration support, and better error handling for a more reliable user experience.

.gitignore

@@ -46,5 +46,7 @@ database/extensions/*.so
 database/extensions/*.dll
 database/extensions/*.dylib
 
+# mcp servers installation directory
+/mcp-servers/
 
 /.cursor