release: v1.0.0 — initial release

- 4 API groups: IpGeolocation (13), ReverseGeocoding (3), Verification (3), NetworkEngineering (7)
- splitIntoPolygons() helper for multi-polygon confidence areas
- BigDataCloudClient.fromEnvironment() reading BIGDATACLOUD_API_KEY
- validatePhone/validatePhoneByIp require explicit country/IP
- Full TypeScript types, dual ESM+CJS build via tsup
- Node 18+ native fetch — zero runtime dependencies
- 4 samples verified against live API