v0.1.17

Second-pass hardening: U+2028/2029 escaping, migration save guard

- MEDIUM: Escape U+2028/U+2029 in buildOverlaySource JSON output —
  these are valid JSON but break JS string literals in pre-ES2019
  engines (Chromium <80, older QtWebEngine). Defense-in-depth.
- MEDIUM: Wrap migration _save() in profiles.js _load() in its own
  try/catch — a full disk or encryption failure during migration
  must not cause the outer catch to discard all loaded profiles.
- Bump to 0.1.17

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>