Add forecasting demand insights trigger + fix RabbitMQ cleanup

Issue 1: Forecasting demand insights not triggered in demo workflow
- Created internal ML endpoint: /forecasting/internal/ml/generate-demand-insights
- Added trigger_demand_insights_internal() to ForecastServiceClient
- Integrated forecasting insights into demo session post-clone workflow
- Now triggers 4 AI insight types: price, safety stock, yield, + demand

Issue 2: RabbitMQ client cleanup error in procurement service
- Fixed: rabbitmq_client.close() → rabbitmq_client.disconnect()
- Added proper cleanup in exception handler
- Error: "'RabbitMQClient' object has no attribute 'close'"

Files modified:
- services/forecasting/app/api/ml_insights.py (new internal_router)
- services/forecasting/app/main.py (register internal router)
- shared/clients/forecast_client.py (new trigger method)
- services/demo_session/app/services/clone_orchestrator.py (+ demand insights)
- services/procurement/app/api/internal_demo.py (fix disconnect)

Expected impact:
- Demo sessions will now generate demand forecasting insights
- No more RabbitMQ cleanup errors in logs
- AI insights count should increase from 1 to 2-3 per session

🤖 Generated with Claude Code

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

services/procurement/app/api/internal_demo.py

@@ -171,7 +171,7 @@ async def _emit_po_approval_alerts_for_demo(
                 # Continue with other POs
 
         # Close RabbitMQ connection
-        await rabbitmq_client.close()
+        await rabbitmq_client.disconnect()
 
         logger.info(
             "PO approval alerts emission completed",
@@ -188,7 +188,12 @@ async def _emit_po_approval_alerts_for_demo(
             virtual_tenant_id=str(virtual_tenant_id),
             exc_info=True
         )
-        # Don't fail the cloning process
+        # Don't fail the cloning process - ensure we try to disconnect if connected
+        try:
+            if 'rabbitmq_client' in locals():
+                await rabbitmq_client.disconnect()
+        except:
+            pass  # Suppress cleanup errors
         return alerts_emitted