Property/fuzz tests for quest_registry weekly streak logic

[mericcintosun]

Context. quest_registry tracks weekly streaks (increment, reset on a gap, preserve best). There are unit tests but no property tests, unlike reputation/rewards.

Tasks

• proptest over arbitrary sequences of completion weeks.
• Invariants: weeks never exceeds consecutive run; best is monotonic; a gap resets to 1.

Files: contracts/quest_registry/src/test.rs.

[Mathew2k-hash]

@Mathew2k-hash has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I'd like to work on this issue because I have experience writing property-based tests for Rust code to validate state transitions and edge cases beyond traditional unit tests. I'll use proptest to generate arbitrary completion-week sequences and verify key invariants: the current streak never exceeds the consecutive run, the best streak is monotonic, and any gap correctly resets the streak to 1. This will strengthen confidence in the weekly streak logic while keeping the tests deterministic, maintainable, and consistent with the existing property-testing approach used in the repository.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Mathew2k-hash to this issue.

[Agencybuilds]

@Agencybuilds has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

i would love the opportunity to work on this issue, i'm motivated . detail oriented , and ready to contribute a solid solution while helping the community grow.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Agencybuilds to this issue.