phundrak
306fa38935
test(infrastructure): implement MockRelayLabelRepository for testing
Create in-memory mock implementation of RelayLabelRepository trait
using HashMap with Arc<Mutex<>> for thread-safe concurrent access.
Includes 8 comprehensive tests covering all trait methods and edge
cases.
Also refactor domain repository module structure to support multiple
repository types (repository.rs → repository/label.rs + mod.rs).
TDD phase: Combined red-green (tests + implementation)
Ref: T037, T038