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>

shared/clients/forecast_client.py

@@ -341,6 +341,53 @@ class ForecastServiceClient(BaseServiceClient):
         }
         return await self.post("forecasting/ml/insights/generate-rules", data=data, tenant_id=tenant_id)
 
+    async def trigger_demand_insights_internal(
+        self,
+        tenant_id: str
+    ) -> Optional[Dict[str, Any]]:
+        """
+        Trigger demand forecasting insights for a tenant (internal service use only).
+
+        This method calls the internal endpoint which is protected by X-Internal-Service header.
+        Used by demo-session service after cloning to generate AI insights from seeded data.
+
+        Args:
+            tenant_id: Tenant ID to trigger insights for
+
+        Returns:
+            Dict with trigger results or None if failed
+        """
+        try:
+            result = await self._make_request(
+                method="POST",
+                endpoint=f"forecasting/internal/ml/generate-demand-insights",
+                tenant_id=tenant_id,
+                data={"tenant_id": tenant_id},
+                headers={"X-Internal-Service": "demo-session"}
+            )
+
+            if result:
+                self.logger.info(
+                    "Demand insights triggered successfully via internal endpoint",
+                    tenant_id=tenant_id,
+                    insights_posted=result.get("insights_posted", 0)
+                )
+            else:
+                self.logger.warning(
+                    "Demand insights internal endpoint returned no result",
+                    tenant_id=tenant_id
+                )
+
+            return result
+
+        except Exception as e:
+            self.logger.error(
+                "Error triggering demand insights via internal endpoint",
+                tenant_id=tenant_id,
+                error=str(e)
+            )
+            return None
+
     # ================================================================
     # Legacy/Compatibility Methods (deprecated)
     # ================================================================