Revert "Fix the double callback call resulting in the Auth code already used screen"

This reverts commit 0f79b1d753.

frontend/src/app/auth/callback/page.tsx

@@ -1,6 +1,6 @@
 "use client"
 
-import { useEffect, useState, Suspense } from "react"
+import { useEffect, useState, useRef, Suspense } from "react"
 import { useRouter, useSearchParams } from "next/navigation"
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
 import { Button } from "@/components/ui/button"
@@ -14,21 +14,17 @@ function AuthCallbackContent() {
   const [status, setStatus] = useState<"processing" | "success" | "error">("processing")
   const [error, setError] = useState<string | null>(null)
   const [purpose, setPurpose] = useState<string>("app_auth")
+  const hasProcessed = useRef(false)
 
   useEffect(() => {
-    const code = searchParams.get('code')
-    const callbackKey = `callback_processed_${code}`
-
-    // Prevent double execution across component remounts
-    if (sessionStorage.getItem(callbackKey)) {
-      console.log('Callback already processed, skipping')
-      return
-    }
-    sessionStorage.setItem(callbackKey, 'true')
+    // Prevent double execution in React Strict Mode
+    if (hasProcessed.current) return
+    hasProcessed.current = true
 
     const handleCallback = async () => {
       try {
         // Get parameters from URL
+        const code = searchParams.get('code')
         const state = searchParams.get('state')
         const errorParam = searchParams.get('error')
         
@@ -41,6 +37,14 @@ function AuthCallbackContent() {
         const detectedPurpose = authPurpose || (storedConnectorType?.includes('drive') ? 'data_source' : 'app_auth')
         setPurpose(detectedPurpose)
         
+        // Debug logging
+        console.log('OAuth Callback Debug:', {
+          urlParams: { code: !!code, state: !!state, error: errorParam },
+          localStorage: { connectorId, storedConnectorType, authPurpose },
+          detectedPurpose,
+          fullUrl: window.location.href
+        })
+        
         // Use state parameter as connection_id if localStorage is missing
         const finalConnectorId = connectorId || state