🔐 Implement robust session persistence to avoid 'are you human' captcha checks

- Add comprehensive session persistence with cookies, localStorage, and sessionStorage
- Implement stealth browser features to reduce bot detection
- Add smartLogin() method that prioritizes saved sessions over fresh logins
- Create session management utilities (refresh, clear, test validity)
- Update enhanced screenshot service to use session persistence
- Add comprehensive documentation and test script
- Support manual login fallback when captcha is encountered
- Sessions stored in .tradingview-session/ directory for Docker compatibility

This solves the captcha problem by avoiding repeated logins through persistent sessions.

lib/enhanced-screenshot.ts

@@ -23,18 +23,30 @@ export class EnhancedScreenshotService {
       // Initialize automation with Docker-optimized settings
       await tradingViewAutomation.init()
 
-      // Check if already logged in
+      // Check if already logged in using session persistence
       const alreadyLoggedIn = await tradingViewAutomation.isLoggedIn()
       
       if (!alreadyLoggedIn) {
-        console.log('Attempting TradingView login...')
-        const loginSuccess = await tradingViewAutomation.login(config.credentials)
+        console.log('No active session found...')
         
-        if (!loginSuccess) {
-          throw new Error('Login failed')
+        // Try to use session persistence first to avoid captcha
+        const sessionTest = await tradingViewAutomation.testSessionPersistence()
+        
+        if (sessionTest.isValid) {
+          console.log('✅ Valid session found - avoiding captcha!')
+        } else {
+          console.log('⚠️ No valid session - manual login may be required')
+          console.log('💡 Using smart login to handle captcha scenario...')
+          
+          // Use smart login which prioritizes session persistence
+          const loginSuccess = await tradingViewAutomation.smartLogin(config.credentials)
+          
+          if (!loginSuccess) {
+            throw new Error('Smart login failed - manual intervention may be required')
+          }
         }
       } else {
-        console.log('Already logged in to TradingView')
+        console.log('✅ Already logged in using saved session')
       }
 
       // Navigate to chart