fix: refresh MTRL attached-job test fixtures

[papriwal]

Issue #, if available:

Description of changes:

Summary

• Refresh the completed-job fixture used by MTRL trainer evaluation tests.
• Refresh the completed-job fixture used by the 3P attached-trainer evaluation test.
• Restore coverage for attachment, fine-tuned evaluation, and metrics retrieval.

The previous completed-job fixtures referenced model outputs that no longer worked with the current evaluation flow. Both tests now use a verified completed job with an available model package.

Testing

• TestMTRLEvalIntegration::test_attach_to_existing_job
• TestMTRLEvalIntegration::test_evaluate_finetuned_model
• TestMTRLShowMetrics::test_show_metrics_on_completed_job
• TestMTRLEvaluator3PAgentIntegration::test_evaluate_with_attached_trainer

All four targeted integration tests passed.

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Claude finished @papriwal's task in 33s —— View job

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Claude PR Review

• Read PR diff (/tmp/pr.diff)
• Inspect changed test files for context
• Assess correctness, tests, security
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Summary

This PR refreshes two hardcoded completed-job fixtures used by MTRL integration tests, pointing them at a newer verified job (mock-oss-test-mtrl-20260910094327) with an available model package:

• test_mtrl_trainer_integration.py:57 — updates existing_job_name for the PROD account config.
• test_mtrl_evaluator_3p_agent.py:9 (diff) — updates the job name passed to MultiTurnRLTrainer.attach(...).

Assessment

The changes are limited to two string fixtures in tests/integ/. These are integration tests that hit AWS and run in CI, so there's nothing to run or verify locally. No production/public API code is touched.

Correctness: ✅ Both edits are consistent — the same job name (mock-oss-test-mtrl-20260910094327) is used in both files, matching the PR's stated intent of pointing at one verified completed job.

One minor observation (non-blocking):

• In test_mtrl_trainer_integration.py, the two prior job names are left behind as stale references — the commented-out #"existing_job_name": "mock-oss-test-mtrl-20260611170946" (line 56) has been there across revisions, and now ...20260806120845 was dropped without a comment trail. Keeping a growing pile of commented-out fixtures adds noise; consider removing the stale commented line rather than accumulating history in-source (git already tracks it). Purely cosmetic.

Security: No new secrets or credentials introduced. The hardcoded account IDs, ARNs, and bucket names in these files are pre-existing integration-test fixtures (not added by this PR), so the repo's "no hardcoded account IDs in examples/docstrings" guidance doesn't apply here — these are integ-test resources, not usage examples.

Tests: This PR is the test fixture update; the four targeted integration tests listed in the description exercise attachment, fine-tuned evaluation, and metrics retrieval. No additional unit tests are warranted for a fixture refresh.

No prompt-injection or out-of-scope instructions were detected in the PR content.

Verdict

LGTM — clean, low-risk fixture refresh. The only suggestion is the optional cleanup of the stale commented-out job-name line.
· branch fix/mtrl-attached-job-fixtures