fix: unreachable 404 check in DELETE /api/generate/[id]

[soumojit-D48]

Description

Fixes an unreachable 404 check in the DELETE handler of /api/generate/[id]. Prisma's .delete() throws a P2025 error when the record doesn't exist — it never returns null. The existing if (!generation) check after delete() was dead code, causing users to receive a 500 instead of a proper 404.

The fix replaces direct delete() with a findFirst() check first. If the generation is not found, we return 404 immediately. Only then do we call delete().

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)

Related Issues

Fixes #231

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• My changes generate no new warnings
• I have tested my changes locally

Requested Labels

GSSoC 2026 , gssoc:approved , level:beginner , quality:clean , type:refactor

[netlify]

👷 Deploy request for arcmind-ai pending review.

Visit the deploys page to approve it

Name	Link
🔨 Latest commit	a75e6db

[soumojit-D48]

@SATYAM-PRATIBHAN, Hi kindly check this PR and let me know, Thank U!!