[S3] Implement cron job that polls Horizon every 10 seconds

[Akshola00]

Description

Add the cron job that calls Horizon on a schedule to check for new contract events.

Deliverables

• SyncService has @Cron(CronExpression.EVERY_10_SECONDS) method syncEvents()
• Calls HorizonService.getTransactions(contractId, cursor)
• Stores the latest-seen cursor in memory between runs to avoid re-processing old events
• Logs how many new events were found each run
• Does not crash if Horizon is unreachable (catches and logs error)
• npm run build passes

Notes

Depends on #47 (SyncModule).

[AvatarMiiDe]

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

I have reviewed the description and I can work on this. Kindly assign this to me, and I would work on it ASAP

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[dolaoluwa574-source]

@dolaoluwa574-source has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Passionate about building reliable software, with experience in backend engineering, APIs, object-oriented programming, and scalable systems.

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[Jerryvic911]

@Jerryvic911 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I'd like to take on this issue. I can implement the cron job to poll Horizon every 10 seconds and handle new contract events reliably within the existing system.

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[Neziahtech]

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

Hello Maintainer, would love to take this issue

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[HuyadO4]

@HuyadO4 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi maintainer, I would love to work on this issue.

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[Sage-senpai]

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

hello, im sage a fullstack blockchain engineer. i would love to work on this issue and guarantee an efficient and effective PR

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[AdityaK9822]

@AdityaK9822 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Please let me work on this issue, PR submission ASAP

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[Ceejaytech25]

@Ceejaytech25 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

GM GM Maintainer, pls can I work on this issue ? ETA - 12hrs

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[drips-wave]

Congratulations, @Ceejaytech25! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

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