fix: add back link to public folders

internal/handler/node.go

@@ -379,7 +379,7 @@ func (h *NodeHandler) PublicMeta(w http.ResponseWriter, r *http.Request) {
 			writeInternalError(w, r, err, "failed to list folder")
 			return
 		}
-		h.renderPublicFolder(w, r, node, children)
+		h.renderPublicFolder(w, r, node, children, false)
 		return
 	}
 	h.renderPublicUnavailable(w, node)
@@ -415,7 +415,7 @@ func (h *NodeHandler) PublicChildMeta(w http.ResponseWriter, r *http.Request) {
 			writeInternalError(w, r, err, "failed to list folder")
 			return
 		}
-		h.renderPublicFolder(w, r, node, children)
+		h.renderPublicFolder(w, r, node, children, true)
 		return
 	}
 	h.renderPublicUnavailable(w, node)
@@ -563,8 +563,12 @@ func (h *NodeHandler) renderPublicPreview(w http.ResponseWriter, node *model.Nod
 </html>`)
 }
 
-func (h *NodeHandler) renderPublicFolder(w http.ResponseWriter, r *http.Request, node *model.Node, children []model.Node) {
+func (h *NodeHandler) renderPublicFolder(w http.ResponseWriter, r *http.Request, node *model.Node, children []model.Node, showBack bool) {
 	token := chi.URLParam(r, "token")
+	backLink := ""
+	if showBack && node.ParentID != nil && *node.ParentID != "" {
+		backLink = `<a class="back-link" href="` + html.EscapeString(h.publicNodeURL(token, *node.ParentID)) + `">← Назад к папке выше</a>`
+	}
 	items := `<div class="empty">В папке пока нет файлов.</div>`
 	if len(children) > 0 {
 		var b strings.Builder
@@ -608,6 +612,9 @@ func (h *NodeHandler) renderPublicFolder(w http.ResponseWriter, r *http.Request,
     h1 { margin: 0; font-size: 22px; line-height: 1.35; font-weight: 800; }
     .meta { margin-top: 6px; color: #9aa7bd; font-size: 14px; }
     main { padding: 24px; }
+    .nav { max-width: 980px; margin: 0 auto 14px; }
+    .back-link { display: inline-flex; align-items: center; min-height: 38px; padding: 0 14px; border: 1px solid #263044; border-radius: 8px; background: #151a2a; color: #c7d2fe; text-decoration: none; font-weight: 700; }
+    .back-link:hover { border-color: #6366f1; background: #191f34; }
     .list { display: grid; gap: 10px; max-width: 980px; margin: 0 auto; }
     .item { display: grid; grid-template-columns: 72px minmax(0, 1fr) auto; gap: 14px; align-items: center; min-height: 58px; padding: 12px 14px; border: 1px solid #263044; border-radius: 10px; background: #151a2a; color: inherit; text-decoration: none; }
     .item:hover { border-color: #6366f1; background: #191f34; }
@@ -624,7 +631,7 @@ func (h *NodeHandler) renderPublicFolder(w http.ResponseWriter, r *http.Request,
       <h1>`+html.EscapeString(node.Title)+`</h1>
       <div class="meta">Публичный просмотр папки</div>
     </header>
-    <main>`+items+`</main>
+    <main><div class="nav">`+backLink+`</div>`+items+`</main>
   </div>
 </body>
 </html>`)