fix(build): copy prompt .md assets to dist after tsc (ENG-232)

package.json

@@ -10,7 +10,7 @@
     "node": ">=20.0.0"
   },
   "scripts": {
-    "build": "tsc --project tsconfig.json",
+    "build": "tsc --project tsconfig.json && node scripts/copy-prompts.js",
     "build:watch": "tsc --project tsconfig.json --watch",
     "dev": "tsx watch src/index.ts",
     "start": "node dist/index.js",

scripts/copy-prompts.js

@@ -0,0 +1,38 @@
+#!/usr/bin/env node
+/**
+ * copy-prompts.js
+ *
+ * Copies Markdown prompt files from src/prompts/ → dist/prompts/.
+ * Run as part of the build pipeline after `tsc`.
+ *
+ * Why this exists:
+ *   TypeScript's compiler only emits .js/.d.ts files — it ignores .md assets.
+ *   PromptLoader resolves prompts from dist/prompts/ at runtime, so we must
+ *   mirror the src/prompts/ tree into dist/ after every build.
+ *
+ * Usage:
+ *   node scripts/copy-prompts.js
+ */
+
+import { cpSync, mkdirSync } from 'fs';
+import { join, dirname } from 'path';
+import { fileURLToPath } from 'url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+const root = join(__dirname, '..');
+const src = join(root, 'src', 'prompts');
+const dest = join(root, 'dist', 'prompts');
+
+mkdirSync(dest, { recursive: true });
+
+cpSync(src, dest, {
+  recursive: true,
+  filter: (source) => {
+    // Only copy .md files and directories
+    return source.endsWith('.md') || !source.includes('.');
+  },
+});
+
+console.log(`✅ Prompts copied: ${src} → ${dest}`);