feat: add role-specific statistics to telemetry and UI (cont. #15234) (#18824)

Co-authored-by: Yuna Seol <yunaseol@google.com>

packages/core/src/code_assist/server.test.ts

@@ -9,6 +9,7 @@ import { CodeAssistServer } from './server.js';
 import { OAuth2Client } from 'google-auth-library';
 import { UserTierId, ActionStatus } from './types.js';
 import { FinishReason } from '@google/genai';
+import { LlmRole } from '../telemetry/types.js';
 
 vi.mock('google-auth-library');
 
@@ -69,6 +70,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     expect(mockRequest).toHaveBeenCalledWith({
@@ -126,6 +128,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     expect(recordConversationOfferedSpy).toHaveBeenCalledWith(
@@ -170,6 +173,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     expect(server.recordCodeAssistMetrics).toHaveBeenCalledWith(
@@ -208,6 +212,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     const mockResponseData = {
@@ -369,6 +374,7 @@ describe('CodeAssistServer', () => {
         contents: [{ role: 'user', parts: [{ text: 'request' }] }],
       },
       'user-prompt-id',
+      LlmRole.MAIN,
     );
 
     // Push SSE data to the stream