Add render_window.js: Python-driven incremental pagination with id+chainIndex state, anchor restore, batch guard and streaming auto-detect; wired through chat_bridge and the page shell.
Windows prefers WebView2, Linux uses QtWebEngine only; pythonnet deps are win32-marked. Each QtWebEngine instance gets its own profile under data/webengine, and Chromium flags are sanitized before QApplication (--no-sandbox accepted only for explicit root/container use).
Import the pre-repair source tree as the history baseline.
Runtime data (data/), virtualenvs, bytecode caches and logs are
gitignored so local secrets and user state stay out of the repo.