fix(slinky): Skip exec scontrol show partition for DynamicNodes

[ravisoundar]

Skip exec scontrol show partition when useDynamicNodes is set

Description

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
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[greptile-apps]

Greptile Summary

This PR fixes a crash that occurred when UseDynamicNodes=true and a topology entry had a Partition configured but no explicit nodes — previously the code would attempt to exec scontrol show partition inside a pod, which is unnecessary (and could fail) in dynamic-node mode.

• engine.go: Adds a guard at the top of getPartitionNodes that, when UseDynamicNodes=true, skips the scontrol exec and returns the sentinel value "\tNodes=NONE".
• slurm.go: Extends parsePartitionNodes with a match[1] == "NONE" check that converts the sentinel into an empty node slice, cleanly propagating a no-nodes result without triggering the existing "partition has no nodes" error path.

Confidence Score: 5/5

Safe to merge; the fix correctly skips the scontrol exec when UseDynamicNodes is enabled and the sentinel value threads through the existing regex parser without error.

Both changed lines are algorithmically sound: the sentinel Nodes=NONE satisfies the regex, parsePartitionNodes captures NONE and returns an empty slice cleanly. The only gap is a missing unit-test case for the new branch.

pkg/engines/slurm/slurm_test.go — the new NONE branch in parsePartitionNodes has no dedicated test case.

Important Files Changed

Filename	Overview
pkg/engines/slinky/engine.go	Adds dynamicShowPartitionNodes sentinel constant and an early-return guard in getPartitionNodes that correctly skips scontrol when UseDynamicNodes=true; guard is untested by existing integration tests (all test topologies supply a PodSelector, so getPartitionNodes is never reached).
pkg/engines/slurm/slurm.go	Adds a match[1] == "NONE" branch in parsePartitionNodes that returns an empty slice; regex correctly matches "\tNodes=NONE" but there is no TestParsePartitionNodes case covering this new branch.

_{Reviews (3): Last reviewed commit: "fix(slinky): Skip exec scontrol show par..." | Re-trigger Greptile}