Normalize and persist articles

[justinmadison]

Summary

Read JSON files, format, and store them in a database

Motivation

JustInsight will need to have articles formated and stored to facilitate processing

Scope

None

Acceptance Criteria

-[ ] test that loads article and verifies the schema

Additional Context

1. Create /etl/normalize.py to:

• Read raw JSON files from ./data/raw/
• Extract and clean fields: title, body, timestamp, source
• Insert into MongoDB collection articles

2. Add connection config via environment variables
3. Write a smoke test that loads one article and verifies the schema