Fix: Remove duplicate maneuver execution code

Remove duplicate code blocks that were executing maneuvers twice.
Fix ensures correct update order:
1. Body RK4 updates
2. Body global coords
3. Spacecraft RK4 updates
4. Maneuver execution (once, with executed flag check)
5. Spacecraft global coords (from updated local_velocity)

This eliminates the redundant 'execute pending maneuvers' and 'compute spacecraft globals' blocks that were duplicated in the code.

src/simulation.cpp

@@ -251,42 +251,10 @@ void update_simulation(SimulationState* sim) {
         }
     }
     
-    // Execute pending maneuvers (before computing globals)
-    for (int i = 0; i < sim->maneuver_count; i++) {
-        Maneuver* maneuver = &sim->maneuvers[i];
-        
-        if (maneuver->executed) {
-            continue;
-        }
-        
-        if (maneuver->craft_index < 0 || maneuver->craft_index >= sim->craft_count) {
-            continue;
-        }
-        
-        Spacecraft* craft = &sim->spacecraft[maneuver->craft_index];
-        
-        if (check_maneuver_trigger(maneuver, craft, sim)) {
-            execute_maneuver(maneuver, craft, sim->time);
-        }
-    }
-    
-    // Compute spacecraft global coordinates (after maneuvers)
-    for (int i = 0; i < sim->craft_count; i++) {
-        Spacecraft* craft = &sim->spacecraft[i];
-        
-        if (craft->parent_index >= 0 && craft->parent_index < sim->body_count) {
-            CelestialBody* parent = &sim->bodies[craft->parent_index];
-            craft->position = vec3_add(parent->position, craft->local_position);
-            craft->velocity = vec3_add(parent->velocity, craft->local_velocity);
-        } else {
-            craft->position = craft->local_position;
-            craft->velocity = craft->local_velocity;
-        }
-    }
-    
     sim->time += sim->dt;
 }
 
+
 // Calculate orbital velocity using vis-viva equation
 // Returns velocity vector for body relative to parent
 static Vec3 calc_orbital_velocity(CelestialBody* body, CelestialBody* parent) {