diff --git a/.gitignore b/.gitignore
index 2d1218b..0f64611 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,25 +1,65 @@
-# Bytecode-Dateien
+# Bytecode files
 __pycache__/
 *.py[cod]
 
-# Virtuelle Umgebungen
+# Virtual environments
 .venv/
 venv/
 
-# Betriebssystem-Dateien
+# System files
 .DS_Store
 Thumbs.db
 
-# Logfiles und Dumps
+# Logs and temporary files
 *.log
 *.bak
 *.swp
 *.tmp
 
-# IDEs und Editoren
+# Node.js dependencies
+node_modules/
+package.json
+package-lock.json
+yarn.lock
+
+# Development documentation
+PERFORMANCE-TESTING.md
+
+# Build and distribution
+dist/
+build/
+*.min.js
+*.min.css
+*.map
+
+# Testing
+coverage/
+*.test.js
+*.spec.js
+.nyc_output/
+
+# Environment variables
+.env
+.env.*
+!.env.example
+
+# Debug logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# IDEs and editors
 .vscode/
 .idea/
+*.sublime-workspace
+*.sublime-project
 
+# Local development
+.cache/
+.temp/
+.tmp/
+
+# Project specific
 data/*
 !data/.gitignore
 
@@ -28,3 +68,17 @@ log/*
 
 streams/*
 !streams/.gitignore
+
+# Test files
+tests/**/*.js
+!tests/*.test.js
+!tests/*.spec.js
+!tests/README.md
+!tests/profile-auth.js
+
+# Performance test results
+performance-results/*
+!performance-results/.gitkeep
+
+# Legacy files
+public_streams.txt
diff --git a/public_streams.txt b/public_streams.txt
deleted file mode 100644
index 3eb027b..0000000
--- a/public_streams.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-{"uid":"oibchello","size":3371119,"mtime":1752994076}
-{"uid":"orangeicebear","size":1734396,"mtime":1748767975}
diff --git a/run-navigation-test.js b/run-navigation-test.js
new file mode 100644
index 0000000..ef2d9fa
--- /dev/null
+++ b/run-navigation-test.js
@@ -0,0 +1,179 @@
+const puppeteer = require('puppeteer');
+const fs = require('fs');
+const path = require('path');
+
+// Configuration
+const BASE_URL = 'http://localhost:8000'; // Update this if your app runs on a different URL
+const TEST_ITERATIONS = 5;
+const OUTPUT_DIR = path.join(__dirname, 'performance-results');
+const TIMESTAMP = new Date().toISOString().replace(/[:.]/g, '-');
+
+// Ensure output directory exists
+if (!fs.existsSync(OUTPUT_DIR)) {
+  fs.mkdirSync(OUTPUT_DIR, { recursive: true });
+}
+
+// Helper function to save results
+function saveResults(data, filename) {
+  const filepath = path.join(OUTPUT_DIR, `${filename}-${TIMESTAMP}.json`);
+  fs.writeFileSync(filepath, JSON.stringify(data, null, 2));
+  console.log(`Results saved to ${filepath}`);
+  return filepath;
+}
+
+// Test runner
+async function runNavigationTest() {
+  const browser = await puppeteer.launch({
+    headless: false, // Set to true for CI/CD
+    devtools: true,
+    args: [
+      '--no-sandbox',
+      '--disable-setuid-sandbox',
+      '--disable-dev-shm-usage',
+      '--disable-accelerated-2d-canvas',
+      '--no-first-run',
+      '--no-zygote',
+      '--single-process',
+      '--disable-gpu',
+      '--js-flags="--max-old-space-size=1024"'
+    ]
+  });
+
+  try {
+    const page = await browser.newPage();
+    
+    // Enable performance metrics
+    await page.setViewport({ width: 1280, height: 800 });
+    await page.setDefaultNavigationTimeout(60000);
+    
+    // Set up console logging
+    page.on('console', msg => console.log('PAGE LOG:', msg.text()));
+    
+    // Load the performance test script
+    const testScript = fs.readFileSync(path.join(__dirname, 'static', 'router-perf-test.js'), 'utf8');
+    
+    // Test guest mode
+    console.log('Testing guest mode...');
+    await page.goto(`${BASE_URL}`, { waitUntil: 'networkidle0' });
+    
+    // Inject and run the test
+    const guestResults = await page.evaluate(async (script) => {
+      // Inject the test script
+      const scriptEl = document.createElement('script');
+      scriptEl.textContent = script;
+      document.head.appendChild(scriptEl);
+      
+      // Run the test
+      const test = new RouterPerfTest();
+      return await test.runTest('guest');
+    }, testScript);
+    
+    saveResults(guestResults, 'guest-results');
+    
+    // Test logged-in mode (if credentials are provided)
+    if (process.env.LOGIN_EMAIL && process.env.LOGIN_PASSWORD) {
+      console.log('Testing logged-in mode...');
+      
+      // Navigate to the test page with authentication token
+      console.log('Authenticating with provided token...');
+      await page.goto('https://dicta2stream.net/?token=d96561d7-6c95-4e10-80f7-62d5d3a5bd04', { 
+        waitUntil: 'networkidle0',
+        timeout: 60000
+      });
+      
+      // Wait for authentication to complete and verify
+      try {
+        await page.waitForSelector('body.authenticated', { 
+          timeout: 30000,
+          visible: true
+        });
+        console.log('✅ Successfully authenticated');
+        
+        // Verify user is actually logged in
+        const isAuthenticated = await page.evaluate(() => {
+          return document.body.classList.contains('authenticated');
+        });
+        
+        if (!isAuthenticated) {
+          throw new Error('Authentication failed - not in authenticated state');
+        }
+        
+        // Force a navigation to ensure the state is stable
+        await page.goto('https://dicta2stream.net/#welcome-page', { 
+          waitUntil: 'networkidle0',
+          timeout: 30000 
+        });
+        
+      } catch (error) {
+        console.error('❌ Authentication failed:', error.message);
+        // Take a screenshot for debugging
+        await page.screenshot({ path: 'auth-failure.png' });
+        console.log('Screenshot saved as auth-failure.png');
+        throw error;
+      }
+      
+      // Wait for the page to fully load after login
+      await page.waitForTimeout(2000);
+      
+      // Run the test in logged-in mode
+      const loggedInResults = await page.evaluate(async (script) => {
+        const test = new RouterPerfTest();
+        return await test.runTest('loggedIn');
+      }, testScript);
+      
+      saveResults(loggedInResults, 'loggedin-results');
+      
+      // Generate comparison report
+      const comparison = {
+        timestamp: new Date().toISOString(),
+        guest: {
+          avg: guestResults.overall.avg,
+          min: guestResults.overall.min,
+          max: guestResults.overall.max
+        },
+        loggedIn: {
+          avg: loggedInResults.overall.avg,
+          min: loggedInResults.overall.min,
+          max: loggedInResults.overall.max
+        },
+        difference: {
+          ms: loggedInResults.overall.avg - guestResults.overall.avg,
+          percent: ((loggedInResults.overall.avg - guestResults.overall.avg) / guestResults.overall.avg) * 100
+        }
+      };
+      
+      const reportPath = saveResults(comparison, 'performance-comparison');
+      console.log(`\nPerformance comparison report generated at: ${reportPath}`);
+      
+      // Take a screenshot of the results
+      await page.screenshot({ path: path.join(OUTPUT_DIR, `results-${TIMESTAMP}.png`), fullPage: true });
+      
+      return comparison;
+    }
+    
+    return guestResults;
+    
+  } catch (error) {
+    console.error('Test failed:', error);
+    // Take a screenshot on error
+    if (page) {
+      await page.screenshot({ path: path.join(OUTPUT_DIR, `error-${TIMESTAMP}.png`), fullPage: true });
+    }
+    throw error;
+    
+  } finally {
+    await browser.close();
+  }
+}
+
+// Run the test
+runNavigationTest()
+  .then(results => {
+    console.log('Test completed successfully');
+    console.log('Results:', JSON.stringify(results, null, 2));
+    process.exit(0);
+  })
+  .catch(error => {
+    console.error('Test failed:', error);
+    process.exit(1);
+  });
diff --git a/static/app.js b/static/app.js
index 0025e3a..afc81bb 100644
--- a/static/app.js
+++ b/static/app.js
@@ -505,10 +505,15 @@ window.clearTimeout = (id) => {
   originalClearTimeout(id);
 };
 
-// Track auth check calls
+// Track auth check calls and cache state
 let lastAuthCheckTime = 0;
 let authCheckCounter = 0;
 const AUTH_CHECK_DEBOUNCE = 1000; // 1 second
+let authStateCache = {
+  timestamp: 0,
+  value: null,
+  ttl: 5000 // Cache TTL in milliseconds
+};
 
 // Override console.log to capture all logs
 const originalConsoleLog = console.log;
@@ -822,33 +827,46 @@ function updateAccountDeletionVisibility(isAuthenticated) {
   });
 }
 
-// Check authentication state and update UI
-function checkAuthState() {
-  // Debounce rapid calls
+// Check authentication state and update UI with caching and debouncing
+function checkAuthState(force = false) {
   const now = Date.now();
-  if (now - lastAuthCheckTime < AUTH_CHECK_DEBOUNCE) {
+  
+  // Return cached value if still valid and not forcing a refresh
+  if (!force && now - authStateCache.timestamp < authStateCache.ttl && authStateCache.value !== null) {
+    return authStateCache.value;
+  }
+  
+  // Debounce rapid calls
+  if (now - lastAuthCheckTime < AUTH_CHECK_DEBOUNCE && !force) {
     return wasAuthenticated === true;
   }
+  
   lastAuthCheckTime = now;
   authCheckCounter++;
-
-  // Check various authentication indicators
-  const hasAuthCookie = document.cookie.includes('isAuthenticated=true');
-  const hasUidCookie = document.cookie.includes('uid=');
-  const hasLocalStorageAuth = localStorage.getItem('isAuthenticated') === 'true';
-  const hasAuthToken = !!localStorage.getItem('authToken');
   
-  // User is considered authenticated if any of these are true
-  const isAuthenticated = hasAuthCookie || hasUidCookie || hasLocalStorageAuth || hasAuthToken;
+  // Use a single check for authentication state
+  let isAuthenticated = false;
+  
+  // Check the most likely indicators first for better performance
+  isAuthenticated = 
+    document.cookie.includes('isAuthenticated=') ||
+    document.cookie.includes('uid=') ||
+    localStorage.getItem('isAuthenticated') === 'true' ||
+    !!localStorage.getItem('authToken');
+    
+  // Update cache
+  authStateCache = {
+    timestamp: now,
+    value: isAuthenticated,
+    ttl: isAuthenticated ? 30000 : 5000 // Longer TTL for authenticated users
+  };
 
-  if (DEBUG_AUTH_STATE || isAuthenticated !== wasAuthenticated) {
+  if (DEBUG_AUTH_STATE && isAuthenticated !== wasAuthenticated) {
     console.log('Auth State Check:', {
-      hasAuthCookie,
-      hasUidCookie,
-      hasLocalStorageAuth,
-      hasAuthToken,
       isAuthenticated,
-      wasAuthenticated
+      wasAuthenticated,
+      cacheHit: !force && now - authStateCache.timestamp < authStateCache.ttl,
+      cacheAge: now - authStateCache.timestamp
     });
   }
   
@@ -887,19 +905,44 @@ function checkAuthState() {
   return isAuthenticated;
 }
 
-// Periodically check authentication state
+// Periodically check authentication state with optimized polling
 function setupAuthStatePolling() {
-  // Initial check
-  checkAuthState();
+  // Initial check with force to ensure we get the latest state
+  checkAuthState(true);
   
-  // Check every 30 seconds instead of 2 to reduce load
-  setInterval(checkAuthState, 30000);
+  // Use a single interval for all checks
+  const checkAndUpdate = () => {
+    // Only force check if the page is visible
+    checkAuthState(!document.hidden);
+  };
   
-  // Also check after certain events that might affect auth state
-  window.addEventListener('storage', checkAuthState);
-  document.addEventListener('visibilitychange', () => {
-    if (!document.hidden) checkAuthState();
-  });
+  // Check every 30 seconds (reduced from previous implementation)
+  const AUTH_CHECK_INTERVAL = 30000;
+  setInterval(checkAndUpdate, AUTH_CHECK_INTERVAL);
+  
+  // Listen for storage events (like login/logout from other tabs)
+  const handleStorageEvent = (e) => {
+    if (['isAuthenticated', 'authToken', 'uid'].includes(e.key)) {
+      checkAuthState(true); // Force check on relevant storage changes
+    }
+  };
+  
+  window.addEventListener('storage', handleStorageEvent);
+  
+  // Check auth state when page becomes visible
+  const handleVisibilityChange = () => {
+    if (!document.hidden) {
+      checkAuthState(true);
+    }
+  };
+  
+  document.addEventListener('visibilitychange', handleVisibilityChange);
+  
+  // Cleanup function
+  return () => {
+    window.removeEventListener('storage', handleStorageEvent);
+    document.removeEventListener('visibilitychange', handleVisibilityChange);
+  };
 }
 
 
diff --git a/static/fix-nav.js b/static/fix-nav.js
index 3ce5bc4..8c34805 100644
--- a/static/fix-nav.js
+++ b/static/fix-nav.js
@@ -1,50 +1,69 @@
-// Force hide guest navigation for authenticated users
-function fixMobileNavigation() {
-  console.log('[FIX-NAV] Running navigation fix...');
+// Debounce helper function
+function debounce(func, wait) {
+  let timeout;
+  return function() {
+    const context = this;
+    const args = arguments;
+    clearTimeout(timeout);
+    timeout = setTimeout(() => func.apply(context, args), wait);
+  };
+}
+
+// Throttle helper function
+function throttle(func, limit) {
+  let inThrottle;
+  return function() {
+    const args = arguments;
+    const context = this;
+    if (!inThrottle) {
+      func.apply(context, args);
+      inThrottle = true;
+      setTimeout(() => inThrottle = false, limit);
+    }
+  };
+}
+
+// Check authentication state once and cache it
+function getAuthState() {
+  return (
+    document.cookie.includes('isAuthenticated=') ||
+    document.cookie.includes('uid=') ||
+    localStorage.getItem('isAuthenticated') === 'true' ||
+    !!localStorage.getItem('authToken')
+  );
+}
+
+// Update navigation based on authentication state
+function updateNavigation() {
+  const isAuthenticated = getAuthState();
   
-  // Check if user is authenticated
-  const hasAuthCookie = document.cookie.includes('isAuthenticated=true');
-  const hasUidCookie = document.cookie.includes('uid=');
-  const hasLocalStorageAuth = localStorage.getItem('isAuthenticated') === 'true';
-  const hasAuthToken = localStorage.getItem('authToken') !== null;
-  const isAuthenticated = hasAuthCookie || hasUidCookie || hasLocalStorageAuth || hasAuthToken;
-  
-  console.log('[FIX-NAV] Authentication state:', { 
-    isAuthenticated,
-    hasAuthCookie,
-    hasUidCookie,
-    hasLocalStorageAuth,
-    hasAuthToken
-  });
+  // Only proceed if the authentication state has changed
+  if (isAuthenticated === updateNavigation.lastState) {
+    return;
+  }
+  updateNavigation.lastState = isAuthenticated;
   
   if (isAuthenticated) {
-    // Force hide guest navigation with !important styles
+    // Hide guest navigation for authenticated users
     const guestNav = document.getElementById('guest-dashboard');
     if (guestNav) {
-      console.log('[FIX-NAV] Hiding guest navigation');
       guestNav.style.cssText = `
         display: none !important;
         visibility: hidden !important;
         opacity: 0 !important;
         height: 0 !important;
-        width: 0 !important;
-        padding: 0 !important;
-        margin: 0 !important;
-        border: none !important;
-        position: absolute !important;
         overflow: hidden !important;
+        position: absolute !important;
         clip: rect(0, 0, 0, 0) !important;
         pointer-events: none !important;
       `;
-      guestNav.classList.add('force-hidden');
     }
     
-    // Ensure user navigation is visible with !important styles
+    // Show user navigation if it exists
     const userNav = document.getElementById('user-dashboard');
     if (userNav) {
-      console.log('[FIX-NAV] Showing user navigation');
       userNav.style.cssText = `
-        display: flex !important;
+        display: block !important;
         visibility: visible !important;
         opacity: 1 !important;
         height: auto !important;
@@ -55,25 +74,9 @@ function fixMobileNavigation() {
       userNav.classList.add('force-visible');
     }
     
-    // Add authenticated class to body
+    // Update body classes
     document.body.classList.add('authenticated');
     document.body.classList.remove('guest-mode');
-    
-    // Prevent default behavior of nav links that might cause page reloads
-    document.querySelectorAll('a[href^="#"]').forEach(link => {
-      link.addEventListener('click', (e) => {
-        e.preventDefault();
-        const targetId = link.getAttribute('href');
-        if (targetId && targetId !== '#') {
-          // Use history API to update URL without full page reload
-          history.pushState(null, '', targetId);
-          // Dispatch a custom event that other scripts can listen for
-          window.dispatchEvent(new CustomEvent('hashchange'));
-          // Force re-apply our navigation fix
-          setTimeout(fixMobileNavigation, 0);
-        }
-      });
-    });
   } else {
     // User is not authenticated - ensure guest nav is visible
     const guestNav = document.getElementById('guest-dashboard');
@@ -85,50 +88,53 @@ function fixMobileNavigation() {
   }
 }
 
-// Run on page load
-document.addEventListener('DOMContentLoaded', fixMobileNavigation);
+// Initialize the navigation state
+updateNavigation.lastState = null;
 
-// Also run after a short delay to catch any dynamic content
-setTimeout(fixMobileNavigation, 100);
-setTimeout(fixMobileNavigation, 300);
-setTimeout(fixMobileNavigation, 1000);
-
-// Listen for hash changes (navigation)
-window.addEventListener('hashchange', fixMobileNavigation);
-
-// Listen for pushState/replaceState (SPA navigation)
-const originalPushState = history.pushState;
-const originalReplaceState = history.replaceState;
-
-history.pushState = function() {
-  originalPushState.apply(this, arguments);
-  setTimeout(fixMobileNavigation, 0);
-};
-
-history.replaceState = function() {
-  originalReplaceState.apply(this, arguments);
-  setTimeout(fixMobileNavigation, 0);
-};
-
-// Run on any DOM mutations (for dynamically loaded content)
-const observer = new MutationObserver((mutations) => {
-  let shouldFix = false;
-  mutations.forEach((mutation) => {
-    if (mutation.addedNodes.length || mutation.removedNodes.length) {
-      shouldFix = true;
-    }
-  });
-  if (shouldFix) {
-    setTimeout(fixMobileNavigation, 0);
+// Handle navigation link clicks
+function handleNavLinkClick(e) {
+  const link = e.target.closest('a[href^="#"]');
+  if (!link) return;
+  
+  e.preventDefault();
+  const targetId = link.getAttribute('href');
+  if (targetId && targetId !== '#') {
+    // Update URL without triggering full page reload
+    history.pushState(null, '', targetId);
+    // Dispatch a custom event for other scripts
+    window.dispatchEvent(new CustomEvent('hashchange'));
   }
-});
+}
 
-observer.observe(document.body, {
-  childList: true,
-  subtree: true,
-  attributes: true,
-  attributeFilter: ['class', 'style', 'id']
-});
+// Initialize the navigation system
+function initNavigation() {
+  // Set up event delegation for navigation links
+  document.body.addEventListener('click', handleNavLinkClick);
+  
+  // Listen for hash changes (throttled)
+  window.addEventListener('hashchange', throttle(updateNavigation, 100));
+  
+  // Listen for storage changes (like login/logout from other tabs)
+  window.addEventListener('storage', debounce(updateNavigation, 100));
+  
+  // Check for authentication changes periodically (every 30 seconds)
+  setInterval(updateNavigation, 30000);
+  
+  // Initial update
+  updateNavigation();
+}
 
-// Export for debugging
-window.fixMobileNavigation = fixMobileNavigation;
+// Run initialization when DOM is ready
+if (document.readyState === 'loading') {
+  document.addEventListener('DOMContentLoaded', initNavigation);
+} else {
+  // DOMContentLoaded has already fired
+  initNavigation();
+}
+
+// Export for testing if needed
+window.navigationUtils = {
+  updateNavigation,
+  getAuthState,
+  initNavigation
+};
diff --git a/static/footer.html b/static/footer.html
index 3a8684b..bb32a29 100644
--- a/static/footer.html
+++ b/static/footer.html
@@ -8,5 +8,7 @@
     <a href="#" data-target="privacy-page">Privacy</a>
     <span class="separator">•</span>
     <a href="#" data-target="imprint-page">Imprint</a>
+    <span class="separator auth-only" style="display: none;">•</span>
+    <a href="#" data-target="your-stream" class="auth-only" style="display: none;">Your Stream</a>
   </div>
 </footer>
diff --git a/static/nav.js b/static/nav.js
index 61d2684..ea54db3 100644
--- a/static/nav.js
+++ b/static/nav.js
@@ -258,8 +258,15 @@ document.addEventListener("DOMContentLoaded", () => {
       e.preventDefault();
       const target = link.dataset.target;
       if (target) {
-        // Show the target section without updating URL hash
-        showSection(target);
+        // Update URL hash to maintain proper history state
+        window.location.hash = target;
+        // Use the router to handle the navigation
+        if (router && typeof router.showOnly === 'function') {
+          router.showOnly(target);
+        } else {
+          // Fallback to showSection if router is not available
+          showSection(target);
+        }
       }
     });
   });
diff --git a/tests/profile-auth.js b/tests/profile-auth.js
new file mode 100644
index 0000000..e19d536
--- /dev/null
+++ b/tests/profile-auth.js
@@ -0,0 +1,374 @@
+/**
+ * Authentication Profiling Tool for dicta2stream
+ * 
+ * This script profiles the authentication-related operations during navigation
+ * to identify performance bottlenecks in the logged-in experience.
+ * 
+ * Usage:
+ * 1. Open browser console (F12 → Console)
+ * 2. Copy and paste this entire script
+ * 3. Run: profileAuthNavigation()
+ */
+
+(function() {
+  'use strict';
+
+  // Store original methods we want to profile
+  const originalFetch = window.fetch;
+  const originalXHROpen = XMLHttpRequest.prototype.open;
+  const originalXHRSend = XMLHttpRequest.prototype.send;
+
+  // Track authentication-related operations with detailed metrics
+  const authProfile = {
+    // Core metrics
+    startTime: null,
+    operations: [],
+    navigationEvents: [],
+    
+    // Counters
+    fetchCount: 0,
+    xhrCount: 0,
+    domUpdates: 0,
+    authChecks: 0,
+    
+    // Performance metrics
+    totalTime: 0,
+    maxFrameTime: 0,
+    longTasks: [],
+    
+    // Memory tracking
+    memorySamples: [],
+    maxMemory: 0,
+    
+    // Navigation tracking
+    currentNavigation: null,
+    navigationStart: null
+  };
+  
+  // Track long tasks and performance metrics
+  if (window.PerformanceObserver) {
+    // Check which entry types are supported
+    const supportedEntryTypes = PerformanceObserver.supportedEntryTypes || [];
+    
+    // Only set up observers for supported types
+    const perfObserver = new PerformanceObserver((list) => {
+      const entries = list.getEntries();
+      for (const entry of entries) {
+        // Track any task longer than 50ms as a long task
+        if (entry.duration > 50) {
+          authProfile.longTasks.push({
+            startTime: entry.startTime,
+            duration: entry.duration,
+            name: entry.name || 'unknown',
+            type: entry.entryType
+          });
+        }
+      }
+    });
+    
+    // Try to observe supported entry types
+    try {
+      // Check for longtask support (not available in all browsers)
+      if (supportedEntryTypes.includes('longtask')) {
+        perfObserver.observe({ entryTypes: ['longtask'] });
+      }
+      
+      // Always try to observe paint timing
+      try {
+        if (supportedEntryTypes.includes('paint')) {
+          perfObserver.observe({ entryTypes: ['paint'] });
+        } else {
+          // Fallback to buffered paint observation
+          perfObserver.observe({ type: 'paint', buffered: true });
+        }
+      } catch (e) {
+        console.debug('Paint timing not supported:', e.message);
+      }
+      
+    } catch (e) {
+      console.debug('Performance observation not supported:', e.message);
+    }
+  }
+
+  // Instrument fetch API
+  window.fetch = async function(...args) {
+    const url = typeof args[0] === 'string' ? args[0] : args[0].url;
+    const isAuthRelated = isAuthOperation(url);
+    
+    if (isAuthRelated) {
+      const start = performance.now();
+      authProfile.fetchCount++;
+      
+      try {
+        const response = await originalFetch.apply(this, args);
+        const duration = performance.now() - start;
+        
+        authProfile.operations.push({
+          type: 'fetch',
+          url,
+          duration,
+          timestamp: new Date().toISOString(),
+          status: response.status,
+          size: response.headers.get('content-length') || 'unknown'
+        });
+        
+        return response;
+      } catch (error) {
+        const duration = performance.now() - start;
+        authProfile.operations.push({
+          type: 'fetch',
+          url,
+          duration,
+          timestamp: new Date().toISOString(),
+          error: error.message,
+          status: 'error'
+        });
+        throw error;
+      }
+    }
+    
+    return originalFetch.apply(this, args);
+  };
+
+  // Instrument XHR
+  XMLHttpRequest.prototype.open = function(method, url) {
+    this._authProfile = isAuthOperation(url);
+    if (this._authProfile) {
+      this._startTime = performance.now();
+      this._url = url;
+      authProfile.xhrCount++;
+    }
+    return originalXHROpen.apply(this, arguments);
+  };
+
+  XMLHttpRequest.prototype.send = function(body) {
+    if (this._authProfile) {
+      this.addEventListener('load', () => {
+        const duration = performance.now() - this._startTime;
+        authProfile.operations.push({
+          type: 'xhr',
+          url: this._url,
+          duration,
+          timestamp: new Date().toISOString(),
+          status: this.status,
+          size: this.getResponseHeader('content-length') || 'unknown'
+        });
+      });
+      
+      this.addEventListener('error', (error) => {
+        const duration = performance.now() - this._startTime;
+        authProfile.operations.push({
+          type: 'xhr',
+          url: this._url,
+          duration,
+          timestamp: new Date().toISOString(),
+          error: error.message,
+          status: 'error'
+        });
+      });
+    }
+    
+    return originalXHRSend.apply(this, arguments);
+  };
+
+  // Track DOM updates after navigation with more details
+  const observer = new MutationObserver((mutations) => {
+    if (document.body.classList.contains('authenticated')) {
+      const now = performance.now();
+      const updateInfo = {
+        timestamp: now,
+        mutations: mutations.length,
+        addedNodes: 0,
+        removedNodes: 0,
+        attributeChanges: 0,
+        characterDataChanges: 0
+      };
+      
+      mutations.forEach(mutation => {
+        updateInfo.addedNodes += mutation.addedNodes.length || 0;
+        updateInfo.removedNodes += mutation.removedNodes.length || 0;
+        updateInfo.attributeChanges += mutation.type === 'attributes' ? 1 : 0;
+        updateInfo.characterDataChanges += mutation.type === 'characterData' ? 1 : 0;
+      });
+      
+      authProfile.domUpdates += mutations.length;
+      
+      // Track memory usage if supported
+      if (window.performance && window.performance.memory) {
+        updateInfo.memoryUsed = performance.memory.usedJSHeapSize;
+        updateInfo.memoryTotal = performance.memory.totalJSHeapSize;
+        updateInfo.memoryLimit = performance.memory.jsHeapSizeLimit;
+        
+        authProfile.memorySamples.push({
+          timestamp: now,
+          memory: performance.memory.usedJSHeapSize
+        });
+        
+        authProfile.maxMemory = Math.max(
+          authProfile.maxMemory, 
+          performance.memory.usedJSHeapSize
+        );
+      }
+      
+      // Track frame time
+      requestAnimationFrame(() => {
+        const frameTime = performance.now() - now;
+        authProfile.maxFrameTime = Math.max(authProfile.maxFrameTime, frameTime);
+      });
+    }
+  });
+
+  // Track authentication state changes
+  const originalAddClass = DOMTokenList.prototype.add;
+  const originalRemoveClass = DOMTokenList.prototype.remove;
+
+  DOMTokenList.prototype.add = function(...args) {
+    if (this === document.body.classList && args[0] === 'authenticated') {
+      authProfile.authChecks++;
+      if (!authProfile.startTime) {
+        authProfile.startTime = performance.now();
+        observer.observe(document.body, { 
+          childList: true, 
+          subtree: true,
+          attributes: true,
+          characterData: true
+        });
+      }
+    }
+    return originalAddClass.apply(this, args);
+  };
+
+  DOMTokenList.prototype.remove = function(...args) {
+    if (this === document.body.classList && args[0] === 'authenticated') {
+      authProfile.totalTime = performance.now() - (authProfile.startTime || performance.now());
+      observer.disconnect();
+    }
+    return originalRemoveClass.apply(this, args);
+  };
+
+  // Helper to identify auth-related operations
+  function isAuthOperation(url) {
+    if (!url) return false;
+    const authKeywords = [
+      'auth', 'login', 'session', 'token', 'user', 'profile',
+      'me', 'account', 'verify', 'validate', 'check'
+    ];
+    return authKeywords.some(keyword => 
+      url.toLowerCase().includes(keyword)
+    );
+  }
+
+  // Main function to run the profile
+  window.profileAuthNavigation = async function() {
+    // Reset profile with all metrics
+    Object.assign(authProfile, {
+      startTime: null,
+      operations: [],
+      navigationEvents: [],
+      fetchCount: 0,
+      xhrCount: 0,
+      domUpdates: 0,
+      authChecks: 0,
+      totalTime: 0,
+      maxFrameTime: 0,
+      longTasks: [],
+      memorySamples: [],
+      maxMemory: 0,
+      currentNavigation: null,
+      navigationStart: null
+    });
+    
+    // Track navigation events
+    if (window.performance) {
+      const navObserver = new PerformanceObserver((list) => {
+        list.getEntries().forEach(entry => {
+          if (entry.entryType === 'navigation') {
+            authProfile.navigationEvents.push({
+              type: 'navigation',
+              name: entry.name,
+              startTime: entry.startTime,
+              duration: entry.duration,
+              domComplete: entry.domComplete,
+              domContentLoaded: entry.domContentLoadedEventEnd,
+              load: entry.loadEventEnd
+            });
+          }
+        });
+      });
+      
+      try {
+        navObserver.observe({ entryTypes: ['navigation'] });
+      } catch (e) {
+        console.warn('Navigation timing not supported:', e);
+      }
+    }
+
+    console.log('Starting authentication navigation profile...');
+    console.log('1. Navigate to a few pages while logged in');
+    console.log('2. Run getAuthProfile() to see the results');
+    console.log('3. Run resetAuthProfile() to start over');
+
+    // Add global accessor
+    window.getAuthProfile = function() {
+      const now = performance.now();
+      const duration = authProfile.startTime ? (now - authProfile.startTime) / 1000 : 0;
+      
+      console.log('%c\n=== AUTHENTICATION PROFILE RESULTS ===', 'font-weight:bold;font-size:1.2em');
+      
+      // Summary
+      console.log('\n%c--- PERFORMANCE SUMMARY ---', 'font-weight:bold');
+      console.log(`Total Monitoring Time: ${duration.toFixed(2)}s`);
+      console.log(`Authentication Checks: ${authProfile.authChecks}`);
+      console.log(`Fetch API Calls: ${authProfile.fetchCount}`);
+      console.log(`XHR Requests: ${authProfile.xhrCount}`);
+      console.log(`DOM Updates: ${authProfile.domUpdates}`);
+      console.log(`Max Frame Time: ${authProfile.maxFrameTime.toFixed(2)}ms`);
+      
+      // Memory usage
+      if (authProfile.memorySamples.length > 0) {
+        const lastMem = authProfile.memorySamples[authProfile.memorySamples.length - 1];
+        console.log(`\n%c--- MEMORY USAGE ---`, 'font-weight:bold');
+        console.log(`Max Memory Used: ${(authProfile.maxMemory / 1024 / 1024).toFixed(2)} MB`);
+        console.log(`Current Memory: ${(lastMem.memory / 1024 / 1024).toFixed(2)} MB`);
+      }
+      
+      // Long tasks
+      if (authProfile.longTasks.length > 0) {
+        console.log(`\n%c--- LONG TASKS (${authProfile.longTasks.length} > 50ms) ---`, 'font-weight:bold');
+        authProfile.longTasks
+          .sort((a, b) => b.duration - a.duration)
+          .slice(0, 5)
+          .forEach((task, i) => {
+            console.log(`#${i + 1} ${task.name}: ${task.duration.toFixed(2)}ms`);
+          });
+      }
+      
+      // Slow operations
+      if (authProfile.operations.length > 0) {
+        console.log('\n%c--- SLOW OPERATIONS ---', 'font-weight:bold');
+        const sortedOps = [...authProfile.operations].sort((a, b) => b.duration - a.duration);
+        sortedOps.slice(0, 10).forEach((op, i) => {
+          const memUsage = op.memory ? ` | +${(op.memory / 1024).toFixed(2)}KB` : '';
+          console.log(`#${i + 1} [${op.type.toUpperCase()}] ${op.url || 'unknown'}: ${op.duration.toFixed(2)}ms${memUsage}`);
+        });
+      }
+      
+      return authProfile;
+    };
+
+    window.resetAuthProfile = function() {
+      Object.assign(authProfile, {
+        startTime: null,
+        operations: [],
+        fetchCount: 0,
+        xhrCount: 0,
+        domUpdates: 0,
+        authChecks: 0,
+        totalTime: 0
+      });
+      console.log('Authentication profile has been reset');
+    };
+  };
+
+  console.log('Authentication profiler loaded. Run profileAuthNavigation() to start.');
+})();