Add testing for telemetry in local dist assets

scripts/verify-dist-no-telemetry.ts

@@ -0,0 +1,57 @@
+import { readFile, stat } from 'node:fs/promises'
+import { extname, resolve } from 'node:path'
+import { glob } from 'glob'
+
+type Pattern = {
+  label: string
+  regex: RegExp
+}
+
+const distDir = resolve('dist')
+const ignoredExtensions = new Set(['.map', '.svg'])
+const telemetryPatterns: Pattern[] = [
+  { label: 'GTM container', regex: /GTM-[A-Z0-9]+/i },
+  { label: 'GTM script', regex: /gtm\.js/i },
+  { label: 'Google Tag Manager', regex: /googletagmanager/i },
+  { label: 'dataLayer', regex: /\bdataLayer\b/ }
+]
+
+const distStats = await stat(distDir).catch(() => null)
+if (!distStats?.isDirectory()) {
+  console.error('dist directory not found. Run pnpm build first.')
+  process.exit(1)
+}
+
+const files = await glob('dist/**/*', { nodir: true })
+const violations: Array<{
+  file: string
+  hits: Array<{ label: string; match: string }>
+}> = []
+
+for (const file of files) {
+  const extension = extname(file).toLowerCase()
+  if (ignoredExtensions.has(extension)) continue
+
+  const content = (await readFile(file)).toString('utf8')
+  const hits = telemetryPatterns
+    .map((pattern) => {
+      const match = content.match(pattern.regex)
+      return match ? { label: pattern.label, match: match[0] } : null
+    })
+    .filter((hit): hit is { label: string; match: string } => hit !== null)
+
+  if (hits.length > 0) {
+    violations.push({ file, hits })
+  }
+}
+
+if (violations.length > 0) {
+  console.error('Telemetry references found in dist assets:')
+  for (const violation of violations) {
+    const formattedHits = violation.hits
+      .map((hit) => `${hit.label} (${hit.match})`)
+      .join(', ')
+    console.error(`- ${violation.file}: ${formattedHits}`)
+  }
+  process.exit(1)
+}