feat: add bacth status label to api endpoints and missing indexes

[mdiapenabc]

Description

• Add status Label to Batch/ContactBatch API. So FE coud display the right labels
• Add contact that Ageout to eligibility so they can transition to over18
• Add indexes for performance

# Install dependencies
npm install && cd backend && npm install

# Run tests (should all pass — no new service logic yet)
cd backend && npm run test

# Verify migration applies cleanly (requires local Postgres)
Run migration: docker compose down -v & docker compose up 
Run data ingestion: npm run job:data-ingestion

[saifrazabc]

Approving for batch status API label