Add URL health view and expose health in data source sync/API

[maxachis]

Summary

• add a derived url_health_view (SQL view + ORM model + enum) to separate URL health from labeling status
• use health-derived fields in data-source sync add/update payload generation (url_status + archive URL)
• expose structured url_health on data source GET responses
• expand data-source update sync prerequisites so health-related source changes trigger updates
• update integration tests for readonly data source GET and data-source sync add/update payload assertions

Testing

• docker compose up -d (from local_database/)
• POSTGRES_USER=test_source_collector_user POSTGRES_PASSWORD=HanviliciousHamiltonHilltops POSTGRES_DB=source_collector_test_db POSTGRES_HOST=127.0.0.1 POSTGRES_PORT=5432 UV_CACHE_DIR=/tmp/uv-cache uv run pytest tests/automated/integration/readonly/api/data_sources/test_get.py tests/automated/integration/tasks/scheduled/impl/sync_to_ds/data_source/test_add.py tests/automated/integration/tasks/scheduled/impl/sync_to_ds/data_source/update/test_update_url.py -q
• result: 3 passed