Adds table-driven branch-coverage unit tests for previously untested pure
helper functions across internal/alerts/config, internal/config,
internal/ai/safety, internal/ai/modelresolution, internal/operationreceipt,
internal/models, internal/securityutil and pkg/securityutil. New test files
only, with no source changes.
Covers alert-config normalization and validation, sensitive-path and
redaction classifiers, URL normalizers, provider model resolution,
operation-receipt decoding, credential masking, and account-to-org role
mapping. 57 TestBranchCov functions in 12 files, all vet and gofmt clean.
rcourtman