节点视觉重构 + 右栏选项折叠 + 撤销按钮/快捷键

- kind 名做成顶边框标牌(legend，边框在文字处断开)
- 去掉「开头」字(仅绿框)、去掉选择标题的项数
- 多出口节点每出口一行严格对齐右侧黄点
- 开头节点改为视口垂直居中(左侧)
- 选择节点右栏选项改为可折叠，点开编辑单个
- 撤销/重做按钮(不可用时灰)+ R自动整理 + Enter加后继

web/static/app.js

@@ -289,14 +289,19 @@
     try { toast("⚠ 操作失败：" + m); } catch (_) {}
   });
 
-  // ---------- 撤销 / 重做（Ctrl+Z / Ctrl+Y） ----------
+  // ---------- 撤销 / 重做 ----------
   let undoStack = [], redoStack = [], snapTimer = null;
-  function snapReset() { undoStack = App.ir ? [JSON.stringify(App.ir)] : []; redoStack = []; }
+  function updateUndoButtons() {
+    const u = $("btn-undo"), r = $("btn-redo");
+    if (u) u.disabled = undoStack.length < 2;
+    if (r) r.disabled = redoStack.length === 0;
+  }
+  function snapReset() { undoStack = App.ir ? [JSON.stringify(App.ir)] : []; redoStack = []; updateUndoButtons(); }
   function flushSnapshot() {
     if (!App.ir) return;
     const cur = JSON.stringify(App.ir);
     if (!undoStack.length || undoStack[undoStack.length - 1] !== cur) {
-      undoStack.push(cur); if (undoStack.length > 60) undoStack.shift(); redoStack = [];
+      undoStack.push(cur); if (undoStack.length > 60) undoStack.shift(); redoStack = []; updateUndoButtons();
     }
   }
   function scheduleSnapshot() { clearTimeout(snapTimer); snapTimer = setTimeout(flushSnapshot, 450); }
@@ -309,29 +314,42 @@
     if (undoStack.length < 2) return;
     redoStack.push(undoStack.pop());
     restoreState(undoStack[undoStack.length - 1]);
-    toast("已撤销");
+    updateUndoButtons(); toast("已撤销");
   }
   function redo() {
     if (!redoStack.length) return;
     const s = redoStack.pop(); undoStack.push(s); restoreState(s);
-    toast("已重做");
+    updateUndoButtons(); toast("已重做");
   }
+  $("btn-undo").onclick = undo;
+  $("btn-redo").onclick = redo;
+
+  // ---------- 快捷键：Ctrl+Z/Y 撤销重做、R 自动整理、Enter 加后继 ----------
   document.addEventListener("keydown", e => {
-    if (!(e.ctrlKey || e.metaKey) || !App.ir) return;
+    if (!App.ir) return;
     const a = document.activeElement;
-    if (a && (a.tagName === "INPUT" || a.tagName === "TEXTAREA")) return;   // 输入框内交给浏览器
-    const k = e.key.toLowerCase();
-    if (k === "z" && !e.shiftKey) { e.preventDefault(); undo(); }
-    else if (k === "y" || (k === "z" && e.shiftKey)) { e.preventDefault(); redo(); }
+    const inInput = a && (a.tagName === "INPUT" || a.tagName === "TEXTAREA");
+    if (e.ctrlKey || e.metaKey) {
+      if (inInput) return;                       // 输入框内的 Ctrl+Z 交给浏览器
+      const k = e.key.toLowerCase();
+      if (k === "z" && !e.shiftKey) { e.preventDefault(); undo(); }
+      else if (k === "y" || (k === "z" && e.shiftKey)) { e.preventDefault(); redo(); }
+      return;
+    }
+    if (e.altKey || inInput) return;
+    if (e.key.toLowerCase() === "r") { e.preventDefault(); doAutoLayout(); }
+    else if (e.key === "Enter" && App.selectedNode) { e.preventDefault(); addSuccessor(App.selectedNode); }
   });
 
   // ---------- 画布工具栏 ----------
-  $("btn-autolayout").onclick = () => {
+  function doAutoLayout() {
     if (!App.ir) return;
     App.ir._layout = null;                 // 清坐标 → render 时按自动布局重排
     GraphUI.render(App.ir, App.selectedNode);
-    App.dirty = true; updateDirty();
-  };
+    GraphUI.focusStart(App.ir);
+    App.dirty = true; updateDirty(); scheduleSnapshot(); toast("已自动整理");
+  }
+  $("btn-autolayout").onclick = doAutoLayout;
   $("btn-addsucc").onclick = () => {
     if (!App.ir || !App.selectedNode) { alert("先在画布上点选一个节点，再点「加后继」。"); return; }
     addSuccessor(App.selectedNode);