fix: resolve bounty issue #1 — implement Stripe PaymentIntent

[bomlinux92-byte]

Summary

Fix for [BOUNTY $350] Implement Secure Payment Gateway and Payment Service — Issue #1

Root cause

The function in was a stub that returned fake payment IDs () instead of integrating with the Stripe API.

Fix

• Replaced the stub with a real Stripe integration using the Stripe Node.js SDK
• Added validation for (required, must be a positive integer in smallest currency unit)
• Added currency default to when not provided (consistent with original behavior)
• Returns (mapped from ) and (mapped from )
• Catches and re-throws Stripe errors (, , etc.) with the original error message preserved
• Added unit tests validating amount validation rules and currency default behavior
• Installed npm package in

Changes

• — Full implementation with Stripe SDK
• — Unit tests for validation logic

Acceptance Criteria met

• ✅ npm package installed, environment variable used — no hardcoded keys
• ✅ is required and must be a positive integer; function throws with descriptive error if missing or invalid
• ✅ defaults to if not provided
• ✅ Real call with
• ✅ Resolved value includes and
• ✅ Stub id generation removed
• ✅ Stripe errors caught and re-thrown with original message preserved
• ✅ Unit tests verify correct arguments passed to

Closes #1