test(email): add structural guard for shared email partials

scripts/check-emails.js

@@ -0,0 +1,27 @@
+#!/usr/bin/env node
+// ponytail: 30-line structural guard, not a render test. Catches drift, not pixels.
+const fs = require('fs');
+const path = require('path');
+
+const dir = path.join(__dirname, '..', 'email');
+const files = fs.readdirSync(dir).filter((f) => f.endsWith('.html'));
+
+const failures = [];
+for (const f of files) {
+  const src = fs.readFileSync(path.join(dir, f), 'utf8');
+  const checks = [
+    [/IMPORT emails\/partials\/header\.(html|tpl)/, 'missing header IMPORT'],
+    [/IMPORT emails\/partials\/footer\.(html|tpl)/, 'missing footer IMPORT'],
+    [/<!-- preheader -->/, 'missing preheader marker'],
+  ];
+  for (const [re, msg] of checks) {
+    if (!re.test(src)) failures.push(`${f}: ${msg}`);
+  }
+}
+
+if (failures.length) {
+  console.error('Email template check FAILED:\n' + failures.join('\n'));
+  process.exit(1);
+}
+
+console.log(`Email template check passed (${files.length} templates).`);