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.

cmd/dnswatcher/main.go

@@ -0,0 +1,56 @@
+// Package main is the entry point for dnswatcher.
+package main
+
+import (
+	"go.uber.org/fx"
+
+	"sneak.berlin/go/dnswatcher/internal/config"
+	"sneak.berlin/go/dnswatcher/internal/globals"
+	"sneak.berlin/go/dnswatcher/internal/handlers"
+	"sneak.berlin/go/dnswatcher/internal/healthcheck"
+	"sneak.berlin/go/dnswatcher/internal/logger"
+	"sneak.berlin/go/dnswatcher/internal/middleware"
+	"sneak.berlin/go/dnswatcher/internal/notify"
+	"sneak.berlin/go/dnswatcher/internal/portcheck"
+	"sneak.berlin/go/dnswatcher/internal/resolver"
+	"sneak.berlin/go/dnswatcher/internal/server"
+	"sneak.berlin/go/dnswatcher/internal/state"
+	"sneak.berlin/go/dnswatcher/internal/tlscheck"
+	"sneak.berlin/go/dnswatcher/internal/watcher"
+
+	_ "github.com/joho/godotenv/autoload"
+)
+
+// Build-time variables injected by linker flags (-ldflags).
+//
+//nolint:gochecknoglobals // build-time variables
+var (
+	Appname   = "dnswatcher"
+	Version   string
+	Buildarch string
+)
+
+func main() {
+	globals.SetAppname(Appname)
+	globals.SetVersion(Version)
+	globals.SetBuildarch(Buildarch)
+
+	fx.New(
+		fx.Provide(
+			globals.New,
+			logger.New,
+			config.New,
+			state.New,
+			healthcheck.New,
+			resolver.New,
+			portcheck.New,
+			tlscheck.New,
+			notify.New,
+			watcher.New,
+			middleware.New,
+			handlers.New,
+			server.New,
+		),
+		fx.Invoke(func(*server.Server, *watcher.Watcher) {}),
+	).Run()
+}