Ad reporting + featured rotates one link + clear campaign form on submit

- Ad reporting (auto-approved ads need a safety valve): new reports.js store
  (dual-mode) + ad_reports table + POST /api/report-ad; a "⚠ report" control on
  served ad slots opens a reason prompt and notifies the admin by email
  (siteConfig.adminEmail / ADMIN_EMAIL).
- Featured links now show ONE link at a time and cycle (true rotation), instead
  of listing all links at once.
- Campaign form now clears EVERY field on submit (target/creative/title/etc.).
  A leftover target URL was carrying into the next campaign — the same reason a
  video short was saved with the wrong (massifly) CTA target.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/tx.html

@@ -33,7 +33,7 @@
     <p><a href="/ledger">← Back to the live ledger</a> · <a href="/contract">Read the contract review</a></p>
   </div>
 </section>
-<script src="/assets/common.js?v=20260906m"></script>
+<script src="/assets/common.js?v=20260907m"></script>
 <script src="/assets/tx.js?v=20260906m"></script>
 </body>
 </html>