docs: align Lab 12 timeline walkthrough and dependency review workflow guide

[cursor]

Description

Updates documentation to match recent code/workflow changes and close high-friction troubleshooting gaps for contributors.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• New lab or capstone project
• Documentation update
• Test improvement
• Breaking change (fix or feature that would cause existing functionality to not work)

Related Issues

Fixes #(issue number)

Changes Made

• Updated docs/walkthroughs/lab12-anomaly-detection-walkthrough.md timeline section to match the actual notebook variable flow in notebooks/lab12_anomaly_detection.ipynb.
• Replaced stale placeholder timeline variables (predictions, time, bytes, scores) with concrete dataframe-backed variables used by the notebook (iso_pred, df['simulated_time'], df['bytes_sent'] + df['bytes_recv'], df['anomaly_score']).
• Added a concise “Common Pitfalls (and Fixes)” subsection for common NameError cases in Colab/local runs.
• Added a repo-specific runbook section to docs/guides/github-workflow-guide.md documenting the current .github/workflows/dependency-review.yml behavior (severity gate, copyleft denylist, PR summary comments), plus troubleshooting guidance.

Testing

Describe how you tested your changes:

• Ran pytest tests/ successfully
• Tested in Docker with docker-compose run test
• Manually tested the feature/fix
• Added new tests for the changes

Manual validation performed:

• Verified workflow behavior against .github/workflows/dependency-review.yml.
• Verified Lab 12 timeline variable semantics by inspecting notebooks/lab12_anomaly_detection.ipynb cells directly.
• pytest is not available in this execution environment (pytest: command not found).

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• New and existing tests pass locally with my changes
• No API keys or secrets are included in the changes

Learning Impact (for lab changes)

If this PR affects labs, describe:

• Skills learners will gain: Correctly wiring Isolation Forest outputs into timeline visualizations; debugging common variable-flow errors in notebook workflows.
• Prerequisites updated: None.
• Estimated time impact: Minimal; improves time-to-success by reducing troubleshooting overhead.

Screenshots (if applicable)

N/A

  

[github-actions]

⚠️ Deprecation Warning: The deny-licenses option is deprecated for possible removal in the next major release. For more information, see issue 997.

Dependency Review

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

Snapshot Warnings

⚠️: No snapshots were found for the head SHA 0c77550.

Ensure that dependencies are being submitted on PR branches and consider enabling retry-on-snapshot-warnings. See the documentation for more information and troubleshooting advice.

Scanned Files

None