Add Oracle Cloud Infrastructure (OCI) 2023/2024/2025 sustainability data

New provider. 139 additive rows for 47 OCI regions (40 commercial + 7 US/UK
gov/DoD); no existing rows changed. Data assembled from:
- Electricity Maps grid mapping (cfe-region, em-zone-id, wt-region-id,
  geolocation, grid carbon intensity) from the project's OCI working data
  (commercial regions only).
- CY2023 renewable-electricity % and PUE from Oracle's CY2023 report.
- FY2024 / FY2025 renewable-electricity % from the Oracle Clean Cloud OCI
  Data Sheet, Fiscal Year 2025 Results (Dec 2025):
  https://www.oracle.com/a/ocom/docs/corporate/citizenship/clean-cloud-oci.pdf

Column mapping:
- provider-cfe-annual = renewable-electricity coverage % (annual, market-based).
- provider-carbon-intensity-market-annual = 0 for region-years at 100% renewable.
- power-usage-effectiveness = CY2023 per-region PUE (2023 rows; Oracle has not
  disclosed newer per-region PUE, so 2024/2025 PUE is left blank).
- grid carbon intensity is the 2023 Electricity Maps value, carried forward to
  2024/2025 (same convention as the AWS/Azure rows).

Gov/DoD regions (us-gov-ashburn-1, us-gov-chicago-1, us-gov-phoenix-1,
us-langley-1, us-luke-1, uk-gov-london-1, uk-gov-cardiff-1) carry RE%/PUE but
have blank Electricity Maps grid columns (no zone assigned yet).

Region keys resolved to identifiers via Oracle's official regions list.
Fiscal year (Jun-May) mapped FY24->2024, FY25->2025. Oracle's tCO2e/$USD
emissions-intensity metric has no schema home and is not imported.

Refs #86

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: adrianco