Protoyard v1.4.2

Fixes from the final reviews of PLAN_010, PLAN_011 and PLAN_012 (AI Diff
Reviewer, local). Texuli stays at 0.14.1.

Security

• gallery build --out and sweep --out go through the output guard.
  --out . or --out prototypes used to empty that folder before the build;
  both commands now refuse the workspace, its parents, its source folders and
  any folder Protoyard did not write, like build, export and showcase.

Fixed

• FilePreview: leaving a file that was still loading for one that loads
  nothing (a host image URL, an archive) no longer stays on "Loading preview…".
• Calendar on phones: if the agenda chunk cannot load (offline, a stale
  deploy), the month calendar shows instead of an empty area.
• SsoButtons under provideSaas({ ports }): the scenarios prop is
  ignored instead of throwing at render; hasSaasRuntime() tells a screen
  which mode it runs in (SAAS_KITS).
• Offline plugin: in vite build --watch, a failed rebuild no longer
  regenerates sw.js over the previous output.
• Full screen: a rejected switch no longer leaves the exit hint pending.