[api] Drop connection instead of crashing when buffer allocation fails (#18803)

esphome/components/api/api_buffer.cpp

@@ -1,13 +1,20 @@
 #include "api_buffer.h"
+#include <new>
 
 namespace esphome::api {
 
-void APIBuffer::grow_(size_t n) {
-  auto new_data = make_buffer(n);
+bool APIBuffer::grow_(size_t n) {
+  // nothrow (no zero-fill) so OOM is reportable; plain new aborts instead
+  // (NEW_OOM_ABORT on ESP8266 Arduino, exception stub on ESP-IDF).
+  // RAMAllocator is no fit here: unique_ptr needs delete[]-compatible memory.
+  std::unique_ptr<uint8_t[]> new_data(new (std::nothrow) uint8_t[n]);
+  if (new_data == nullptr)
+    return false;
   if (this->size_)
     std::memcpy(new_data.get(), this->data_.get(), this->size_);
   this->data_ = std::move(new_data);
   this->capacity_ = n;
+  return true;
 }
 
 }  // namespace esphome::api