[Contracts] Implement Basis Points Allocation Percentage Verification

[ONEONUORA]

Description

Implement logic inside the plan setup methods to check allocation integrity:

• Iterate over the input beneficiaries list.
• Sum up their allocation shares.
• Ensure the sum strictly equals 10000 (representing 100.00%).

Acceptance Criteria

• Rejects transaction if sum is not 10,000.
• Rejects if any beneficiary has a share of 0.
• Proper error code returned (Error::InvalidAllocationShares).

[drips-wave]

Congratulations, @Joseph-1-Duro! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Joseph-1-Duro: 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.

Warning

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[grantfox-oss]

🦊 GrantFox — @Joseph-1-Duro has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #829)
2. Your PR will be reviewed by the Fracverse maintainers

Good luck! Track your progress on GrantFox.

[ONEONUORA]

@Joseph-1-Duro
Pls update on this issue
You will be unassign in 6 hours