[Prod DB Integration] Article Synchronization Orchestrator Script

[Enniwhere]

Description:
Create the main synchronization script that coordinates sitemap fetching, article comparison, JSON fetching, database updates, deletion of missing articles, and vector index updates.

Acceptance criteria:

• Script src/scripts/sync_articles.py with CLI arguments: --dry-run, --batch-size (default: 100), --debug
• Fetches all sitemaps and builds set of current article URLs
• Compares sitemap lastmod against database changed_at to identify new/updated articles
• Fetches article JSON from {url}.json for each changed article with retry logic (3 attempts, exponential backoff)
• Processes updates in batches with per-article error handling (log error, skip article, continue batch)
• Identifies articles in database but missing from all sitemaps and deletes them
• After all article updates complete, triggers vector index update
• Logs summary statistics: articles checked, new, updated, deleted, failed, vector indexes updated
• Dry-run mode logs actions without database modifications
• Exit code 0 on success, 1 on critical failure (e.g., cannot connect to DB)

Technical details:

• Use structured logging with article_id, url, and error details
• Add progress logging every N articles (e.g., "Processed 500/2000 articles...")

Design:
Optional details on design for context.