Fix diagnostic checking ui

Author: xlight05

workspaces/ballerina/ballerina-extension/src/features/ai/service/design/design.ts

@@ -50,6 +50,7 @@ const sdk = new NodeSDK({
 });
 sdk.start();
 
+//TODO: Tool name, types and uesd in both ext and visualizer to display, either move to core or use visualizer as view only.
 export async function generateDesignCore(params: GenerateAgentCodeRequest, eventHandler: CopilotEventHandler): Promise<void> {
     const isPlanModeEnabled = params.isPlanMode;
     const messageId = params.messageId;

workspaces/ballerina/ballerina-visualizer/src/views/AIPanel/components/AIChat/index.tsx

@@ -462,7 +462,7 @@ const AIChat: React.FC = () => {
                     }
                     return newMessages;
                 });
-            } else if (response.toolName === "DiagnosticsTool") {
+            } else if (response.toolName === "getCompilationErrors") {
                 setMessages((prevMessages) => {
                     const newMessages = [...prevMessages];
                     if (newMessages.length > 0) {
@@ -589,9 +589,10 @@ const AIChat: React.FC = () => {
                     }
                     return newMessages;
                 });
-            } else if (response.toolName === "DiagnosticsTool") {
+            } else if (response.toolName === "getCompilationErrors") {
                 const diagnosticsOutput = response.toolOutput;
-                const errors = diagnosticsOutput?.diagnostics?.filter((d: any) => d.severity === 1) || [];
+                // Backend already filters for errors only (severity === 1), so no need to filter again
+                const errors = diagnosticsOutput?.diagnostics || [];
                 const errorCount = errors.length;
 
                 setErrorCount(errorCount);