- Add section 9 to data-sources-inventory.md covering live API quirks:
Eurostat SDMX city labels response shape, ONS CSV download path (observations
API 404s), US Census ACS place endpoint, GeoNames cities15000 bulk format
- Add population coverage summary table and DuckDB glob limitation note
- fix(extract): census_usa + geonames write empty placeholder when credentials
absent so SQLMesh staging models don't fail with "no files found"
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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