fix: update token retrieval logic in handleRedirectCallback and remove unused parseSSE function

frontend/src/App.tsx

@@ -165,29 +165,15 @@ async function handleRedirectCallback(): Promise<string | null> {
   })
 
   const result = await response.json()
-  if (response.ok && result.access_token) {
-    setLocalToken(result.access_token)
-    return result.access_token
+  const token = result.id_token || result.access_token
+  if (response.ok && token) {
+    setLocalToken(token)
+    return token
   }
 
   throw new Error(result.error_description || 'OIDC callback failed')
 }
 
-function parseSSE(text: string, onData: (chunk: string) => void) {
-  const events = text.split('\n\n')
-  for (const event of events) {
-    const trimmed = event.trim()
-    if (!trimmed) continue
-    const lines = trimmed.split('\n')
-    const dataLines = lines
-      .filter((line) => line.startsWith('data:'))
-      .map((line) => line.replace(/^data:\s?/, ''))
-    if (dataLines.length) {
-      onData(dataLines.join('\n'))
-    }
-  }
-}
-
 function App() {
   const [messages, setMessages] = useState<Message[]>([])
   const [input, setInput] = useState('')