Extend session lifetime to 7 days

Overrides PHP's default session.gc_maxlifetime (typically 1h on servers)
so sessions survive inactivity without relying on remember-me.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

config/packages/framework.yaml

@@ -3,7 +3,10 @@ framework:
     secret: '%env(APP_SECRET)%'
 
     # Note that the session will be started ONLY if you read or write from it.
-    session: true
+    session:
+        gc_maxlifetime: 604800
+        cookie_lifetime: 604800
+        cookie_samesite: 'lax'
 
     #esi: true
     #fragments: true