ModuleNotFoundError: No module named 'comfy'

This error occurs when a script or custom node tries to import from the core `comfy` package, but Python cannot find it. This almost always happens because a script or a `git clone` command was executed from the wrong directory, or a custom node is placed incorrectly. The `comfy` module is not a pip package; it is the core folder of ComfyUI itself.

• Running a custom node's `install.py` script directly instead of launching ComfyUI.
• Cloning a custom node directly into the root ComfyUI folder instead of `custom_nodes/`.
• Running ComfyUI from outside its root directory (e.g., system path issues).