Add generated data quality report

[Bmowville]

Adds a generated data quality report for the Titanic SQLite pipeline output.

Summary:

• Add a Markdown quality report generator for row count, expected columns, duplicate PassengerId values, missing values, and numeric ranges.
• Add validator checks for the generated quality report.
• Update CI to generate and verify the quality report from a clean pipeline run.
• Update README and pipeline contracts with the new report path and run step.

Validation:

• python pipelines/01_ingest_to_sqlite.py
• python scripts/generate_data_quality_report.py
• python scripts/validate_outputs.py
• python -m compileall pipelines scripts

Closes #4