Fix/report window period

[pchieneye]

Closes #604

---

Fix/report window period

What changed

• Added deterministic report-period resolution for reports submitted while an offering’s reporting window is open.
• Reports within the same open window now canonicalize to the window’s end timestamp, so out-of-order submissions map to the same effective period.
• Added a regression test covering reports arriving before, inside, and around the window boundary.

Files updated

• lib.rs
• test_period_id_boundary.rs

[drips-wave]

@pchieneye Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits