docs: update 6-3-contracts.md

[habib424]

Drafted by Ship Ship 🚢 — confidence 🟢 high

What changed

Added a single sentence to the "Contracts List" section explaining that the page defaults to showing Active and Draft contracts, with users able to adjust the filter to see terminated or other statuses.

Source PRs

• axolotl#4112 — feat(contracts): default contracts filter to Active and Draft

How to use this PR

1. Review the diff against the existing article — focus on accuracy and customer voice.
2. Merge if it reads well. Edit and push to this branch if it needs adjustment.
3. Close without merging if the article doesn't actually need this update.

Once we have a track record of clean drafts, we'll graduate to auto-merge with a delay buffer. For now: human-in-the-loop.