refactor(ui): delete legacy static website and refresh documentation

s2s-client/.gitignore

@@ -6,7 +6,7 @@
 .idea/
 *.swp
 
-# Static HTTP server logs (we don't ship them)
+# Server logs
 *.log
 
 # Python
@@ -14,8 +14,6 @@ __pycache__/
 *.pyc
 .venv/
 venv/
-node_modules/
-!package-lock.json
 
 # Local-only replica deploy script (never tracked)
 deploy_replica.py