feat: Electrobun Svelte+WGPU prototype (Dawn GPU confirmed on Linux)

- Svelte 5 frontend with Catppuccin Mocha theme, 2 project cards
- Electrobun v1.16.0 with bundleWGPU: true (Dawn on Linux x64)
- WebKitGTK webview + WGPU surface coexistence confirmed
- CPU: 6.5% idle (CSS animation + WebKitGTK overhead)
- Port 9760 for dev server (project convention)

ui-electrobun/svelte.config.js

@@ -0,0 +1,5 @@
+import { vitePreprocess } from "@sveltejs/vite-plugin-svelte";
+
+export default {
+	preprocess: vitePreprocess(),
+};