v2.18.0-beta.42 — security update after an audit

A security update, following an independent audit of the whole tree.

Fixed:

• a case where a pinned container could be updated anyway
• a damaged settings.json could put the container into a restart loop instead of being set aside
• two output paths in the new list view (STATUS_VIEW=list)
• local backup bundles were written world-readable while holding channel credentials — owner-only now

The detail is held back until the matching stable release is out: until then everyone on :latest is still running the old code.

Same code as beta.41, re-tagged within the hour — that build's changelog section was missing the bold leads the what's-new message is built from, so updating to it produced no message at all. Use this one.

Worth testing: whether pins hold, and the list view.