Fix Markov simulation chart display issue

- Fix circular import issue by moving simulation_manager to app/__init__.py
- Enhance get_wealth_evolution to include inequality metrics data
- Add get_inequality_evolution method for complete chart data
- Update API to return top10_shares and capital_shares in evolution data
- Modify onSimulationComplete to fetch and populate charts with complete data
- Fix simulation threading to properly mark completion state
- Add test script to verify chart data generation

The charts now properly display simulation results by fetching complete
evolution data when simulation completes, resolving the empty diagrams issue.

app/routes/api.py

@@ -13,7 +13,7 @@ from typing import Optional
 
 from app import socketio
 from app.models import SimulationManager, SimulationParameters
-from app.routes.main import simulation_manager
+from app import simulation_manager
 
 api_bp = Blueprint('api', __name__)
 
@@ -95,6 +95,9 @@ def start_simulation(simulation_id: str):
         if simulation.is_running:
             return jsonify({'error': 'Simulation already running'}), 400
         
+        # Mark simulation as running
+        simulation.is_running = True
+        
         # Start simulation in background thread
         def run_simulation_background():
             try:
@@ -125,6 +128,9 @@ def start_simulation(simulation_id: str):
                     # Small delay to allow real-time visualization
                     time.sleep(0.01)
                 
+                # Mark as completed
+                simulation.is_running = False
+                
                 # Emit completion
                 socketio.emit('simulation_complete', {
                     'simulation_id': simulation_id,
@@ -132,6 +138,7 @@ def start_simulation(simulation_id: str):
                 }, room=f'simulation_{simulation_id}')
                 
             except Exception as e:
+                simulation.is_running = False
                 current_app.logger.error(f"Error in simulation thread: {str(e)}")
                 socketio.emit('simulation_error', {
                     'simulation_id': simulation_id,
@@ -254,10 +261,15 @@ def get_simulation_data(simulation_id: str):
         
         # Include evolution data if requested
         if request.args.get('include_evolution', '').lower() == 'true':
+            # Get complete inequality data
+            ineq_iterations, gini_over_time, top10_over_time, capital_over_time = simulation.get_inequality_evolution()
+            
             response_data['evolution'] = {
                 'iterations': iterations,
                 'total_wealth': total_wealth,
-                'gini_coefficients': gini_coefficients
+                'gini_coefficients': gini_coefficients,
+                'top10_shares': top10_over_time,
+                'capital_shares': capital_over_time
             }
         
         return jsonify(response_data)