Root cause: innerHTML does not execute <script> tags in modern browsers.
The _analysis.html and polling.html fragments had inline <script> blocks
that were silently dropped, causing:
- Confirm form's submitJob() undefined → form submitted as normal GET
back to '/' (user saw 'New Conversion Session' instead of polling)
- Polling page's poll() never started → stuck on 'Waiting for backend...'
Fix:
- Stripped all <script> tags from _analysis.html and polling.html
- Moved all JS logic into index.html (executed on page load)
- initConfirmForm() attaches submit/change listeners after analysis HTML
is injected via innerHTML
- initPolling() attaches poll timer + reuse button handlers after
polling fragment is injected
- Polling fragment replaces step1/analysis content while keeping
base.html header/footer intact
- Reuse buttons now use onclick attached via JS (not inline)
