Initial scaffold with per-nameserver DNS monitoring model

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.

go.mod

@@ -0,0 +1,39 @@
+module sneak.berlin/go/dnswatcher
+
+go 1.25.5
+
+require (
+	github.com/99designs/basicauth-go v0.0.0-20230316000542-bf6f9cbbf0f8
+	github.com/go-chi/chi/v5 v5.2.5
+	github.com/go-chi/cors v1.2.2
+	github.com/joho/godotenv v1.5.1
+	github.com/prometheus/client_golang v1.23.2
+	github.com/spf13/viper v1.21.0
+	go.uber.org/fx v1.24.0
+)
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/fsnotify/fsnotify v1.9.0 // indirect
+	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.66.1 // indirect
+	github.com/prometheus/procfs v0.16.1 // indirect
+	github.com/sagikazarmark/locafero v0.11.0 // indirect
+	github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8 // indirect
+	github.com/spf13/afero v1.15.0 // indirect
+	github.com/spf13/cast v1.10.0 // indirect
+	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
+	go.uber.org/dig v1.19.0 // indirect
+	go.uber.org/multierr v1.10.0 // indirect
+	go.uber.org/zap v1.26.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.2 // indirect
+	go.yaml.in/yaml/v3 v3.0.4 // indirect
+	golang.org/x/sys v0.35.0 // indirect
+	golang.org/x/text v0.28.0 // indirect
+	google.golang.org/protobuf v1.36.8 // indirect
+)