fix: Handle ProgramRuleAction without a ProgramRule when importing [DHIS2-13920]

[david-mackessy]

Issue

Importing a ProgramRuleAction with no ref to a ProgramRule results in NullPointerException & the import finishes unexpectedly.
Import/Export app UI gets this response when importing async:

[
    {
        "level": "ERROR",
        "category": "METADATA_IMPORT",
        "message": "Cannot invoke \"org.hisp.dhis.programrule.ProgramRule.getProgram()\" because \"rule\" is null",
        "completed": true,
        "uid": "iZ4eX8gGB0e",
        "id": "iZ4eX8gGB0e",
        "time": "2026-08-25T10:49:28.757"
    }
]

Cause

Import payload has ProgramRuleAction with no ref to a ProgramRule. Causes a NPE and abruptly stops the import job.

Fix

Check that a ProgramRuleAction has a ProgramRule before continuing the import flow.
Report an error if there is no ProgramRule attached, which allows the import job to continue.

Testing

Added tests that check importing a payload with a ProgramRuleAction without a ProgramRule ref.

• atomicMode=ALL -> no objects imported and object report contains error detailing the missing ref issue
• atomicMode=NONE -> valid objects still imported and invalid ProgramRuleAction ignored with an error report

[david-mackessy]

used the next available error code

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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