Move MAX_VELOCITY_M_S constant to class scope

Co-authored-by: dfeen87 <158860247+dfeen87@users.noreply.github.com>

Author: Copilot

include/PropulsionPhysicsEngine.hpp

@@ -10,6 +10,7 @@ class PropulsionPhysicsEngine {
     static constexpr float MAX_THRUST_kN = 2500.0f;
     static constexpr float MIN_MASS_KG = 100.0f;
     static constexpr float MIN_VELOCITY_M_S = -20000.0f;
+    static constexpr float MAX_VELOCITY_M_S = 20000.0f;  // ~72,000 km/h
     static constexpr uint32_t PHYSICS_DT_MS = 10;
 
     void init();

src/physics/propulsion_physics_engine.cpp

@@ -170,7 +170,6 @@ bool PropulsionPhysicsEngine::is_state_physically_plausible(
         return false;
 
     // Velocity sanity check (magnitude per component)
-    constexpr float MAX_VELOCITY_M_S = 20000.0f; // ~72,000 km/h
     if (std::abs(state.velocity_m_s[0]) > MAX_VELOCITY_M_S ||
         std::abs(state.velocity_m_s[1]) > MAX_VELOCITY_M_S ||
         std::abs(state.velocity_m_s[2]) > MAX_VELOCITY_M_S)