fix: Session auth, sidebar toggle, and dependencies table

- Change session.cookie_samesite from Strict to Lax for Authelia compatibility
- Redesign sidebar toggle with separate collapse/expand buttons
- Add script to create missing ticket_dependencies table
- Add .env.example template
- Add check for missing .env with helpful error message

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

middleware/AuthMiddleware.php

@@ -25,8 +25,10 @@ class AuthMiddleware {
             // Configure secure session settings
             ini_set('session.cookie_httponly', 1);
             ini_set('session.cookie_secure', 1); // Requires HTTPS
-            ini_set('session.cookie_samesite', 'Strict');
+            ini_set('session.cookie_samesite', 'Lax'); // Lax allows redirects from Authelia
             ini_set('session.use_strict_mode', 1);
+            ini_set('session.gc_maxlifetime', 18000); // 5 hours
+            ini_set('session.cookie_lifetime', 0); // Until browser closes
 
             session_start();
         }