fix(generic-specializer): prevent panic on missing kptfile status

[pulkitvats2007-crypto]

Summary

The generic-specializer was crashing when processing Kptfiles that do not contain a status block.
This PR adds a defensive nil check to safely handle such cases and allow reconciliation to continue.

---

Root Cause

kptfile.Status is an optional pointer.
The controller assumed it is always present and directly accessed:

kptfile.Status.Conditions

When Status == nil, this caused a runtime panic:
invalid memory address or nil pointer dereference.

In Go, dereferencing a nil pointer always results in a runtime panic if not checked beforehand, because the pointer does not reference any valid memory location oai_citation:0‡codegenes.

---

Fix

Added a nil check before accessing Status.Conditions:

if kptfile.Status != nil {
    // safely process conditions
}

Testing

• Added unit test: reconciler_nil_status_test.go
• Validates that reconciliation succeeds with a status-less Kptfile
• Confirms no panic occurs

---

Impact

• Prevents controller crashes during reconciliation
• Unblocks PackageRevisions created from fresh or manually authored packages
• Eliminates silent failure loops and stuck resources
• Improves overall reliability of the generic-specializer in production

[nephio-prow]

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[nephio-prow]

Hi @pulkitvats2007-crypto. Thanks for your PR.

I'm waiting for a nephio-project member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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