What is the best setup for AI-assisted coding, including: IDE (Cursor, VSCode, Windsurf, Zed, etc). AI assistant (LLM) like Claude, Gemini 2.5 Pro, OpenAI, DeepSeek. MCP, rulesets, extensions, tools, workflow, and anything else?

And what kind of project are you building/maintaining with it (framework, language, deployment infra, aprox # of users)?

It seems like there are a lot of options out there, and a lot look very similar, maybe just different styles