Documentation

Add clear docstrings and comments to the code below. Document what each function does, its parameters, and return value. Comment only the non-obvious logic — don't state the obvious. Keep the code itself unchanged. Code: [PASTE]

Write a clear step-by-step SOP for this process: [PROCESS]. Include: purpose, who does it, tools needed, numbered steps written so a new person could follow them, and common mistakes to avoid. Keep steps action-first ("Click X," not "You should click X").