feat(linear-static-3d-euler-beam): step 23 - hdf5-results-writer

include/fesa/io/hdf5/hdf5_results_writer.hpp

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "fesa/results/results_writer.hpp"
+
+namespace fesa {
+
+// Writes schema-v0 output while keeping backend and platform types private.
+class Hdf5ResultsWriter final : public ResultsWriter {
+public:
+    Status write(
+        const std::filesystem::path& outputPath,
+        const Domain& domain,
+        const AnalysisState& state,
+        const std::vector<Diagnostic>& diagnostics) override;
+};
+
+} // namespace fesa