fix: resolve in-container ctest script from env before importing the CLI

[wyli]

The in-container ctest -S argument imported holoscan_cli just to locate the ctest script, so test failed in images without an importable CLI even though HOLOSCAN_CLI_CTEST_SCRIPT is already forwarded into the container. Use the forwarded env value first and keep the import only as the fallback.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Improved containerized test execution by resolving the CTest script path at runtime.
  • Respects the configured HOLOSCAN_CLI_CTEST_SCRIPT value, with a fallback when it is not set.

• Tests

  • Updated coverage to verify environment-based CTest script resolution in containers.

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 0eef941c-43b7-4969-b1fd-abdb4780ea6f

📥 Commits

Reviewing files that changed from the base of the PR and between 2cfdd04 and 4e6bd2c.

📒 Files selected for processing (2)

• src/holoscan_cli/commands/test_cmd.py
• tests/unit/test_container_recursion.py

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Walkthrough

The containerized ctest -S command now resolves its script from HOLOSCAN_CLI_CTEST_SCRIPT at runtime, falling back to HoloscanCLI.DEFAULT_CTEST_SCRIPT. Documentation and the corresponding unit assertion were updated.

Changes

Container ctest script resolution

Layer / File(s)	Summary
Runtime script selection and validation src/holoscan_cli/commands/test_cmd.py, tests/unit/test_container_recursion.py	The generated in-container command prefers HOLOSCAN_CLI_CTEST_SCRIPT, falls back to the default script path, and tests the updated command rendering.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: resolving the in-container ctest script from an environment variable before importing the CLI.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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