fixed problem with '/' causing loading issues with application

internal/api/router.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"net/http/httputil"
 	"net/url"
+	"strings"
 
 	"github.com/go-chi/chi/v5"
 	chimiddleware "github.com/go-chi/chi/v5/middleware"
@@ -232,7 +233,12 @@ func mustParseURL(raw string) *url.URL {
 func spaHandler(staticFiles fs.FS) http.Handler {
 	fileServer := http.FileServer(http.FS(staticFiles))
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		_, err := staticFiles.Open(r.URL.Path)
+		// fs.FS paths must not have a leading slash.
+		path := strings.TrimPrefix(r.URL.Path, "/")
+		if path == "" {
+			path = "."
+		}
+		_, err := staticFiles.Open(path)
 		if err != nil {
 			r.URL.Path = "/"
 		}