Refactor authentication and session management

- Removed old llm_login and session scripts, replacing them with a new structure for handling SSO login and session management.
- Introduced a new prompt system for collecting SSO redirect URLs, ensuring compliance with security protocols.
- Implemented a robust backend notification system for tracking scan initiation.
- Enhanced browser profile configuration and resource management for improved session handling.
- Added utility functions for environment variable checks and logging.
- Updated the overall architecture to improve maintainability and readability.

lib/utils/backend_client.py

@@ -0,0 +1,21 @@
+import requests
+from config import BACKEND_URL
+
+def notify_backend(target_url):
+    # Backend에 스캔 시작을 알림
+    try:
+        response = requests.post(
+            f"{BACKEND_URL}/start", params={"url": target_url}, timeout=5
+        )
+        if response.status_code == 200:
+            print(f"✅ Backend notified: {response.text}")
+        else:
+            print(f"⚠️ Backend notification failed: {response.status_code}")
+    except requests.exceptions.ConnectionError:
+        print(
+            f"⚠️ Backend server not available at {BACKEND_URL}. Continuing without notification."
+        )
+    except requests.exceptions.Timeout:
+        print(f"⚠️ Backend notification timed out. Continuing without notification.")
+    except Exception as e:
+        print(f"⚠️ Failed to notify backend: {e}")