Add application state reset on login page mount

- Reset all application state on login page
- Clear authentication and session storage
- Reset graph, backend, and settings state
- Ensure clean environment for new session
- Centralized state reset in navigation service

lightrag_webui/src/services/navigation.ts

@@ -1,4 +1,7 @@
 import { NavigateFunction } from 'react-router-dom';
+import { useAuthStore, useBackendState } from '@/stores/state';
+import { useGraphStore } from '@/stores/graph';
+import { useSettingsStore } from '@/stores/settings';
 
 class NavigationService {
   private navigate: NavigateFunction | null = null;
@@ -7,7 +10,42 @@ class NavigationService {
     this.navigate = navigate;
   }
 
+  /**
+   * Reset all application state to ensure a clean environment.
+   * This function should be called when:
+   * 1. User logs out
+   * 2. Authentication token expires
+   * 3. Direct access to login page
+   */
+  resetAllApplicationState() {
+    console.log('Resetting all application state...');
+    
+    // Clear authentication state
+    localStorage.removeItem('LIGHTRAG-API-TOKEN');
+    sessionStorage.clear();
+    useAuthStore.getState().logout();
+    
+    // Reset graph state
+    const graphStore = useGraphStore.getState();
+    graphStore.reset();
+    graphStore.setGraphDataFetchAttempted(false);
+    graphStore.setLabelsFetchAttempted(false);
+    
+    // Reset backend state
+    useBackendState.getState().clear();
+    
+    // Reset retrieval history while preserving other user preferences
+    useSettingsStore.getState().setRetrievalHistory([]);
+  }
+
+  /**
+   * Navigate to login page after resetting application state
+   * to ensure a clean environment for the next session
+   */
   navigateToLogin() {
+    // Reset state before navigation
+    this.resetAllApplicationState();
+    
     if (this.navigate) {
       this.navigate('/login');
     }