feat(solver-bootstrap): step 3 — core-ids-and-diagnostics

include/fesa/core/vec3.hpp

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <cmath>
+
+namespace fesa {
+
+struct Vec3 final {
+    double x;
+    double y;
+    double z;
+};
+
+[[nodiscard]] inline bool is_finite(const Vec3 value) noexcept {
+    return std::isfinite(value.x) && std::isfinite(value.y) &&
+           std::isfinite(value.z);
+}
+
+}  // namespace fesa