Story 5.2: Video Widget Width Customization

Implements configurable video widget widths for small and large dock layouts:
- Add widgetWidthSm and widgetWidthMd world settings (defaults: 83px, 150px)
- Add width dropdown selectors in Director's Board UI
- Apply width settings to participant avatars via CSS custom properties
- Update strip width/height calculations to use custom widths
- Add localization strings for widget width settings
- Add CSS styling for widget width dropdown controls
- Fix Handlebars template syntax for select element selected values

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

module.js

@@ -150,6 +150,23 @@ Hooks.once("init", () => {
     onChange: () => roleRenderer?.rerenderStrip(),
   });
 
+  // Story 5.2: Video widget width customization — world-scoped settings for small and large tile widths
+  adapter.settings.register("widgetWidthSm", {
+    scope: "world",
+    config: false,
+    type: String,
+    default: "83",
+    onChange: () => roleRenderer?.rerenderStrip(),
+  });
+
+  adapter.settings.register("widgetWidthMd", {
+    scope: "world",
+    config: false,
+    type: String,
+    default: "150",
+    onChange: () => roleRenderer?.rerenderStrip(),
+  });
+
   // Construct data layer — constructors are side-effect-free
   // Note: ScenePresetManager is constructed in 'ready' hook after visibilityManager is available
   stateStore = new StateStore(adapter.settings);