Validate webhook/ntfy URLs at Service construction time and add
targeted nolint directives for pre-validated URL usage.
Fix goimports formatting in tlscheck_test.go.
Full project structure following upaas conventions: uber/fx DI, go-chi
routing, slog logging, Viper config. State persisted as JSON file with
per-nameserver record tracking for inconsistency detection. Stub
implementations for resolver, portcheck, tlscheck, and watcher.
