- 3 Tier 1 medium/low-confidence providers with keyword anchoring - Dual-located in providers/ and pkg/providers/definitions/ - Registry test passes
- OpenAI: add sk-svcacct- and legacy T3BlbkFJ patterns - Anthropic: add api03 AA suffix and sk-ant-admin01- pattern - Sync both to pkg/providers/definitions/ for go:embed
- Provider, Pattern, VerifySpec, RegistryStats structs in schema.go - UnmarshalYAML validates format_version >= 1 and last_verified non-empty - Three reference YAML files: openai, anthropic, huggingface