Fix/idempotency cleanup scheduler

[GiftedGiftB]

close #179

Description

This PR addresses the issue where expired idempotency records were accumulating in the database by properly invoking and managing the StartIdempotencyCleanupScheduler.

Changes Made:

• Scheduler Activation: Integrated the StartIdempotencyCleanupScheduler call in backend/main.go using a 1-hour interval.
• Graceful Shutdown: Added context.Context and *sync.WaitGroup arguments to the scheduler. It now appropriately stops the ticker and completes the goroutine during the application's shutdown sequence.
• Logging Statistics: The scheduler now logs the exact number of expired idempotency records it clears every tick (Cleaned up expired idempotency records).
• Fix: Resolved an invalid type assertion panic (c.Writer.(*gin.ResponseWriter)) within idempotency.go.

Acceptance Criteria Met

• Call StartIdempotencyCleanupScheduler in main.go
• Set cleanup interval to 1 hour
• Add graceful shutdown for cleanup goroutine
• Log cleanup statistics

Testing

• Verified compilation success using go build main.go.
• Application boot sequence accurately initializes the scheduler alongside background workers.

[drips-wave]

@GiftedGiftB Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits

[parkerwinner]

fix conflict @GiftedGiftB