usage-extension: credit last-week contribution

[tmustier]

Summary

• add explicit contributor credit for the Last Week tab in the 0.1.6 changelog entry
• keep the existing implementation unchanged

Context

The Last Week tab landed via PR #14 from @ttttmr. This follow-up adds the missing attribution note in the changelog before the 0.1.6 release notes are finalized.

[tmustier]

Findings

No findings. This change is limited to usage-extension/CHANGELOG.md and does what the PR description says: add contributor credit for the 0.1.6 “Last Week” tab.

Non-issues

• usage-extension/CHANGELOG.md:5 — Adding - Thanks @ttttmr as a separate bullet is consistent with the existing changelog style used in earlier entries.
• No code, package, or version changes are present; that matches the stated docs-only intent and is not a problem.

Verdict

correct — no P0-P2 issues; the diff is a docs-only changelog update that matches the stated goal.