[Contracts] Implement Grace Period Verification Checks

[ONEONUORA]

Description

Implement verification methods to confirm a plan has timed out:

• Read current ledger timestamp.
• Compare it with last_ping + grace_period.
• Return boolean status.

Acceptance Criteria

• Exposes query methods for external reads.
• Rejects claim operations if grace period has not elapsed yet.

[firstJOASH]

@firstJOASH has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

i'd like to solve this issue
kindly assign me

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[Zarmaijemimah]

@Zarmaijemimah has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi I’ll love to work on this issue please kindly assign thank you.

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[divicbold47]

@divicbold47 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi Boss, I can fix this. Thank you

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[drips-wave]

Congratulations, @Zarmaijemimah! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Zarmaijemimah: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

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[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Zarmaijemimah's PR #879 was approved and merged by @ONEONUORA.

🏆 @Zarmaijemimah: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (48 total points). Track your full progress on GrantFox.

👏 Great work, @Zarmaijemimah! Keep contributing to Fracverse.

[drips-wave]

This issue has been completed by @Zarmaijemimah as part of the Stellar Wave Program's 6th Wave 🥳

😎 @Zarmaijemimah: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

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