Replace type assertions in test code

Replace TypeScript `as` type assertions in tests with type-safe @total-typescript/shoehorn

Test suites with large mock objects where only a few properties matter and traditional `as` is heavy-handed

• · test files with `as Type` or `as unknown as Type` assertions

• · refactored test files using fromPartial() or fromAny()

• · @total-typescript/shoehorn

Test files use TypeScript; npm/yarn package manager available

fromExact() forces full objects—use only for swap-back; loses intentional wrong-data semantics if fromAny() omitted

• · Total TypeScript author (Matt Pocock) pattern
• · Maintains autocomplete even with fromAny()
• · Works with partial + wrong-type scenarios