feat(materials): add campaign materials overlay for sessions

Let GMs manage and show images over the scene from the editor and control panel, with zoom tools, help docs, and full ru/en i18n.

Co-authored-by: Cursor <cursoragent@cursor.com>

vite.config.ts

@@ -54,6 +54,7 @@ export default defineConfig(({ mode }) => {
           presentation: path.resolve(__dirname, 'app/renderer/presentation.html'),
           control: path.resolve(__dirname, 'app/renderer/control.html'),
           sceneDescription: path.resolve(__dirname, 'app/renderer/sceneDescription.html'),
+          materials: path.resolve(__dirname, 'app/renderer/materials.html'),
         },
       },
     },