`bun desktop-prod` (clean) wipes everything including the HF model cache, so
every fresh-install emulation re-downloads multi-GB weights — slow and bandwidth
-heavy, and the exact pain users on flaky networks hit. --keep-models wipes
app/backend data, logs, and webview state for an honest first-run, but KEEPS the
model cache so the weights aren't re-pulled. Ignored under --keep-data (which
keeps everything). Adds the `desktop-prod:keep-models` convenience script.
Scripts-only package.json change — no deps, bun.lock unaffected.
Co-authored-by: mergetest <test@local>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
