refactor(slurm): simplify preflight and run preparation

[nabinchha]

📋 Summary

Simplify Slurm submission preflight, run preparation ownership, and runtime readiness tests without changing behavior or public APIs.

🔗 Related Issue

Follow-up cleanup after #1044.

🔄 Changes

• Reuse one check for unrecognized column and processor types during submission preflight.
• Close preparation resources with one finally block, including when preparation fails.
• Use the backend's stored artifact publisher directly instead of passing it through private helpers; remove an always-false helper argument.
• Consolidate Bash readiness test setup, including the manifest test, and parameterize two late-success cases.
• Cover plugin processors in the existing overlay-dependency preflight test.

🧪 Testing

• make test passes (not run; affected modules tested)
• Unit tests updated; 75 service and benchmark tests and 15 readiness tests passed
• E2E tests added/updated (not applicable)
• Ruff lint and format checks, diff check, and pre-commit hooks passed

✅ Checklist

• Follows commit message conventions
• Commits are signed off (DCO)
• If I am an external contributor, the linked issue is open and labeled triaged (not applicable)
• Architecture docs updated (not applicable)

---

Description updated with AI

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge; no blocking issues were found.

Summary

Simplifies Slurm preflight checks, run preparation, and readiness tests without changing public APIs.

• Submission checks plugin columns and processors with one rule.
• Readiness tests run through one shared Bash setup.
• Run setup closes resources and uses its stored publisher.

No actionable issues found in the changes since the previous review. No previous findings were supplied. Tests were not run during this review.

_{Reviews (2) · Last reviewed commit: "refactor(slurm): simplify run preparatio..." · Reviewed by Greptile}