feat(oidc): support token refreshing via offline_access scope

- refactored code
- moved api/v1/auth to auth/
- security enhancement
- env example update
- default jwt ttl changed to 24 hours

internal/auth/block_page.go

@@ -0,0 +1,22 @@
+package auth
+
+import (
+	"html/template"
+	"net/http"
+
+	_ "embed"
+)
+
+//go:embed block_page.html
+var blockPageHTML string
+
+var blockPageTemplate = template.Must(template.New("block_page").Parse(blockPageHTML))
+
+func WriteBlockPage(w http.ResponseWriter, status int, error string, logoutURL string) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	blockPageTemplate.Execute(w, map[string]string{
+		"StatusText": http.StatusText(status),
+		"Error":      error,
+		"LogoutURL":  logoutURL,
+	})
+}