Describe every setting under its name

Properties can carry a one-line description, set with
NamedProperty.description for mods, a ConfigManager.property overload for
the client's config, and a helper in ModLayout. PropertyList rows show it
under the setting's name in muted text. Every mod, HUD layout, general,
UI style and animation setting now has one.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/main/java/org/saturnclient/config/property/NamedProperty.java

@@ -8,4 +8,12 @@ public class NamedProperty {
         this.name = name;
         this.prop = value;
     }
+
+    /**
+     * Sets the line shown under the setting's name.
+     */
+    public NamedProperty description(String description) {
+        this.prop.description = description;
+        return this;
+    }
 }