Moved the NodeJS version of the application to the app/ directory.

app/backend/src/template-service.ts

@@ -0,0 +1,41 @@
+import { existsSync, readFileSync } from "node:fs";
+import { join } from "node:path";
+import nunjucks from "nunjucks";
+import type { ImageSelection, UsageTemplate } from "./types";
+
+const findAppNewRoot = (): string => {
+  const candidates = [join(__dirname, "../../.."), join(__dirname, "../..")];
+
+  for (const candidate of candidates) {
+    if (existsSync(join(candidate, "templates.json"))) {
+      return candidate;
+    }
+  }
+
+  throw new Error("Unable to resolve app-new template root");
+};
+
+export class TemplateService {
+  private readonly appNewRoot = findAppNewRoot();
+
+  private readonly env = nunjucks.configure(join(this.appNewRoot, "templates"), {
+    autoescape: false,
+    noCache: true
+  });
+
+  private readonly templates: UsageTemplate[] = JSON.parse(
+    readFileSync(join(this.appNewRoot, "templates.json"), "utf8")
+  ) as UsageTemplate[];
+
+  public getTemplates(): UsageTemplate[] {
+    return this.templates;
+  }
+
+  public render(templateFile: string, selection: ImageSelection): string {
+    return this.env.render(templateFile, selection);
+  }
+
+  public buildSkuExport(skus: string[]): string {
+    return `[\n${skus.map((sku) => `\t\"${sku}\"`).join(",\n")}\n]`;
+  }
+}