refactor routing into a modular and versioned structure

Move inline route definitions from main.go into a dedicated internal/routes package. This organization introduces support for API versioning (v1) and separates endpoint logic into specialized modules for administration and bug reporting.

internal/routes/v1/v1.go

@@ -0,0 +1,34 @@
+package v1
+
+import (
+	"net/http"
+
+	"emly-api-go/internal/handlers"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/jmoiron/sqlx"
+)
+
+// NewRouter returns a chi.Router with all /v1 routes mounted.
+// Add new API versions by creating an analogous package (e.g. v2) and
+// mounting it alongside this one in internal/routes/routes.go.
+func NewRouter(db *sqlx.DB) http.Handler {
+	r := chi.NewRouter()
+
+	r.Use(func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			w.Header().Set("X-Server", "emly-api-go")
+			w.Header().Set("X-Powered-By", "Pure Protogen sillyness :3")
+			next.ServeHTTP(w, r)
+		})
+	})
+
+	r.Get("/health", handlers.Health(db))
+
+	r.Route("/api", func(r chi.Router) {
+		registerAdmin(r, db)
+		registerBugReports(r, db)
+	})
+
+	return r
+}