Add HTTP layer and server setup

- Add strict configuration management (no fallbacks)
- Create HTTP router with Chi and CORS middleware
- Implement health check endpoint
- Add main entry point with database initialization
- Server runs on configurable host and port

internal/infrastructure/http/router.go

@@ -0,0 +1,29 @@
+package http
+
+import (
+	"net/http"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
+	"github.com/go-chi/cors"
+)
+
+func NewRouter(corsOrigins string) *chi.Mux {
+	r := chi.NewRouter()
+
+	r.Use(middleware.Logger)
+	r.Use(middleware.Recoverer)
+	r.Use(cors.Handler(cors.Options{
+		AllowedOrigins:   []string{corsOrigins},
+		AllowedMethods:   []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
+		AllowedHeaders:   []string{"Accept", "Authorization", "Content-Type"},
+		AllowCredentials: true,
+	}))
+
+	r.Get("/api/v1/health", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(`{"status":"ok"}`))
+	})
+
+	return r
+}