fix(layout): grow specs without contiguous reallocations

native/include/lua/layout.h

@@ -138,21 +138,20 @@ constexpr uint16_t NO_LABEL = 0xFFFF;
 class Tree {
 public:
   std::vector<Node> nodes;
-  std::vector<Spec> specs;
+  std::deque<Spec> specs;
   const char* error = nullptr;
   uint16_t focus = NONE;
 
-  // Growth doubling needs the old and new buffers live at once, which is the
-  // allocation that fails first on a tight heap. One reservation covers a
-  // typical screen so a build reallocates only if it genuinely gets large.
-  static constexpr size_t RESERVE = 64;
+  // Growth doubling needs the old and new node buffers live at once, which is
+  // the allocation that fails first on a tight heap. One reservation covers a
+  // small screen so a build reallocates only if it genuinely gets large.
+  static constexpr size_t NODE_RESERVE = 64;
 
   void reset() {
     focus = NONE;
     nodes.clear();
     specs.clear();
-    nodes.reserve(RESERVE);
-    specs.reserve(RESERVE);
+    nodes.reserve(NODE_RESERVE);
     labelAt.clear();
     labels.clear();
     styles.clear();