feat(routes-f): polynomial evaluator

[davedumto]

Summary

Evaluate a polynomial at given x values using Horner's method.

Requirements

• POST { coefficients: number[], x: number | number[] }
• coefficients highest-degree first
• Return { results }
• Tests verify Horner evaluation against expanded form

Scope Constraint - READ BEFORE STARTING

All files for this task must live inside app/api/routes-f/. This includes the route handler, helpers/utilities, types, and tests. Do NOT modify, import from, or add files to lib/, utils/, types/, components/, or anywhere else outside app/api/routes-f/. If you need shared logic, duplicate it inside your subfolder. Keeping everything scoped to this folder is intentional - it keeps these tasks independent and mergeable in any order.

[drips-wave]

Congratulations, @KevinMB0220! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @KevinMB0220: 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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[KevinMB0220]

@davedumto can you close this issue?