Split api/openapi.yaml schemas into api/schemas.yaml so structs can be
generated independently from the API server code. Models now generate
into internal/model/ via oapi-codegen, with the server referencing them
through import-mapping. Moved PtrTo helper to internal/utils and removed
storage.ReportSummary in favor of model.TestSummary.
CalculateScore now accepts a forWhitelist flag to handle whitelist
scoring logic separately. The final blacklist grade combines both
RBL and DNSWL results using MinGrade for a more accurate reputation
assessment.
