Challenge 1: Update a Single Field — Possible Solution
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db.products.updateOne(
  { name: "Laptop" },
  { $set: { price: 799 } }
)

WHY THIS WORKS AS AN ANSWER
------------------------------
The filter { name: "Laptop" } identifies which document to update,
and $set: { price: 799 } changes ONLY the price field, leaving every
other field on that document (name, category, stock, etc.) completely
untouched. Using $set here is essential, not optional — per this
chapter's gotcha, writing { price: 799 } as the update WITHOUT $set
would be interpreted as a full replacement document, and the product
would lose every field except price entirely.