WebUI Architecture Cleanup (#19541)

* webui: architecture foundation (non-MCP core refactors)

* chore: update webui build output

tools/server/webui/src/lib/utils/data-url.ts

@@ -0,0 +1,10 @@
+/**
+ * Creates a base64 data URL from MIME type and base64-encoded data.
+ *
+ * @param mimeType - The MIME type (e.g., 'image/png', 'audio/mp3')
+ * @param base64Data - The base64-encoded data
+ * @returns A data URL string in format 'data:{mimeType};base64,{data}'
+ */
+export function createBase64DataUrl(mimeType: string, base64Data: string): string {
+	return `data:${mimeType};base64,${base64Data}`;
+}