Fallback pipeline to refresh the bound tracks parquet when the main ingestion is unavailable. It: 1. Loads Airtable assets, keeping East Africa devices (Zanzibar, Kenya, Mozambique, Malawi, Tanzania) active since 2024-01-01 2. Pulls the last 90 days of PDS trips and filters to those IMEIs 3. Reads the latest bound tracks parquet from cloud, finds new trip IDs, and downloads missing tracks in parallel 4. Aggregates points to 10-minute medians, binds with existing tracks, deduplicates, and uploads a versioned parquet back to cloud storage