Two windows on one data folder each kept their own copy of the settings and accounts, and the one that saved last undid what the other had saved. The owner's decision (#216): one window per data folder. - WindowClaim (gclo.ViewModels): a window holds window.lock in its data folder while it is open, shared with nobody. Windows gives it up when the process ends, however it ends. A folder that cannot be written to holds no claim and stops no window from opening. - A second start finds the claim, asks the open window to come to the front through an event named after the folder, and ends before any window or file of its own exists. The open window comes out of the taskbar and before the other windows. - The claim is given up first thing when the window closes, so a start right after closing opens a window of its own. - Another data folder is another claim: the dev channel beside the stable one, and GCLO_DATA_DIR. The command line makes no claim. - README, threat model (review log), CLAUDE.md. Included, from the review of this pull request: - fix(app): the claim on the data folder never stops a start, and is given up when no window came of it Closes #216 Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>