Data ingestion pipeline for primary sources.

1. load data into cloud data store
2. remove PII
3. filter unused attributes
4. formatting and missing values
5. enrichment

Start by examining the repository structure and any existing data-loading entry points; the issue does not name files, tests, or a source format. Clarify the cloud data store, primary sources, PII-removal rules, unused attributes, formatting, missing-value handling, and enrichment requirements. Done should be defined by agreed ingestion behavior and validation for each listed step.

由索引模型根据 Issue 内容生成。