feat(visa-sponsors): United States provider (USCIS H-1B Employer Data Hub)

[type0labs-dev]

What

Adds a us visa-sponsor provider backed by the USCIS H-1B Employer Data Hub yearly export — employers with H-1B petition approvals, the closest public equivalent of a sponsor register for the US.

• Latest fiscal year discovered by probing h1b_datahubexport-<year>.csv downwards from next year (FY2023 is the newest published today; FY2024+ gets picked up automatically)
• One row per employer×NAICS in the source → aggregated per employer, initial+continuing approvals summed; zero-approval and empty-employer rows dropped
• route: "H-1B", typeRating: "H-1B employer (FY2023: N approvals)", city/state mapped to the location fields
• Catalog + docs table updated

Evidence

• Live run: 27,146 employers parsed from the FY2023 export in ~5s (sanity: GOOGLE LLC, Mountain View CA, 2,460 approvals)
• 5 unit tests: NAICS aggregation, empty-employer and zero-approval filtering, missing-location tolerance, year-probing fallback, no-year-available error

Notes

• This lists sponsorship history (approvals in the last published FY), which is the practical signal a candidate needs; the JD-facing register the UK has doesn't exist for the US.
• Docs table will conflict trivially with feat(visa-sponsors): Netherlands provider (IND public register) #662 (NL) — happy to rebase whichever lands second.

Checks

biome ci . clean · shared + orchestrator typechecks · provider tests 5/5 · same 5 pre-existing client test files fail on clean main in my env (locale/timing), unrelated.

🤖 Generated with Claude Code

[DaKheera47]

LGTM! Would need the merge like you mentioned