CaseTalk now protects your work against data loss when a save is interrupted.

Previously, saving a project, repository, diagram, or text/rich-text/expression file overwrote the existing file directly. If CaseTalk closed unexpectedly during a save (a crash, power loss, or the process being killed), the file could be left half-written and corrupted. Saves that failed slowly (a locked file, a disconnected network drive, or a full disk) could also make the application appear frozen.

Phase 0 (done): every file is now written to a temporary file first and then swapped into place in a single atomic step, so the original is never truncated. If the write or the swap fails, the original file is left intact. This covers repositories, diagrams, projects, and text/rich-text/expression files, and works on local disks as well as network and Parallels shares.

Phase 1 (in progress): a per-session working area keeps a continuously auto-saved copy of your open work on local disk, separate from your real files. If CaseTalk closes unexpectedly, on the next start it can offer to recover the unsaved work, including brand-new projects that were never saved to disk yet. Remaining work: routing auto-save into the working area, promoting it on Save, the startup recovery prompt, and automatic cleanup of old working areas.

Design notes: Doc/SESSION_WORKSPACE_SAVE_ARCHITECTURE.md