Fix port-forward cleanup to only kill specific process (#405)

Previously, `send-integration-task` and `send-libpng-task` used
`pkill -f "kubectl port-forward"` which killed ALL kubectl port-forward
processes. This was problematic when other port-forwards were running.

Now each target captures the PID of the port-forward it starts and kills
only that specific process when done.

Author: hbrodin

Makefile

@@ -132,23 +132,23 @@ send-integration-task:
 		echo "Error: CRS namespace not found. Deploy first with 'make deploy'."; \
 		exit 1; \
 	fi
-	kubectl port-forward -n $${BUTTERCUP_NAMESPACE:-crs} service/buttercup-ui 31323:1323 &
-	@sleep 3
-	./orchestrator/scripts/task_integration_test.sh
-	pkill -f "kubectl port-forward" || true
-	exit 0
+	@kubectl port-forward -n $${BUTTERCUP_NAMESPACE:-crs} service/buttercup-ui 31323:1323 & \
+	PORT_FORWARD_PID=$$!; \
+	sleep 3; \
+	./orchestrator/scripts/task_integration_test.sh; \
+	kill $$PORT_FORWARD_PID 2>/dev/null || true
 
 send-libpng-task:
 	@echo "Running libpng task..."
 	@if ! kubectl get namespace $${BUTTERCUP_NAMESPACE:-crs} >/dev/null 2>&1; then \
 		echo "Error: CRS namespace not found. Deploy first with 'make deploy'."; \
 		exit 1; \
 	fi
-	kubectl port-forward -n $${BUTTERCUP_NAMESPACE:-crs} service/buttercup-ui 31323:1323 &
-	@sleep 3
-	./orchestrator/scripts/task_crs.sh
-	pkill -f "kubectl port-forward" || true
-	exit 0
+	@kubectl port-forward -n $${BUTTERCUP_NAMESPACE:-crs} service/buttercup-ui 31323:1323 & \
+	PORT_FORWARD_PID=$$!; \
+	sleep 3; \
+	./orchestrator/scripts/task_crs.sh; \
+	kill $$PORT_FORWARD_PID 2>/dev/null || true
 
 # Development targets
 lint: