Fix submenu arrow: flexbox centering, proper spacing

- Use display: flex + align-items: center on dropdown-toggle
- gap: 0.75rem between text and arrow
- Remove float: right and margin-top hack
- chevron-right: flex-shrink: 0, font-size: 0.7rem

.gitignore

@@ -21,6 +21,9 @@ admin/storage/geoip/
 admin/storage/stats.json
 var/
 
+# Runtime-compiled theme assets (generated by scssphp, read-only)
+themes/*/assets/css_compiled/
+
 # Runtime-compiled theme assets
 public/themes/