WIP Migrate Activation to Tensor

include/backend/cuda_backend.cuh

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "backend/backend.hpp"
+#include "backend/tensor.hpp"
+
+namespace CUDANet::Backend {
+
+class CUDABackend : public IBackend {
+public:
+    // Memory management
+    void* allocate(size_t bytes) override;
+    void deallocate(void* ptr) override;
+
+    // Layer operations
+    void relu(CUDANet::Backend::Tensor &tensor) override;
+    void sigmoid(CUDANet::Backend::Tensor &tensor) override;
+    void softmax(CUDANet::Backend::Tensor &tensor, CUDANet::Backend::Tensor &temp_max, CUDANet::Backend::Tensor &temp_sum) override;
+
+private:
+    static constexpr int BLOCK_SIZE = 256;
+};
+
+}  // namespace CUDANet::Backend