"Reopen projects on startup" only saved window groups, so windows opened with New Window were lost. The saved session now lists every open project window (groups with their tabs and selection, single windows on their own), and the previous run's session is read before this run first overwrites it, so the startup project can't replace it before the other windows are restored.
Project windows only joined a tab group when merged explicitly or restored at startup; the macOS "Prefer tabs when opening documents" setting was never read, so opening another project or a workspace always created a separate window.
New project windows now follow that preference: with Always they join the active project window's tab group (forming one if needed) and are selected; with In Full Screen they do so only while the active window is full screen; with Manually they stay separate. This covers every path that creates a project window — Open, recent projects, workspaces, drag and drop, and opening from the command line or Finder — while LightEdit windows and restored groups keep their behaviour. New Workspace now opens through the same Open project in policy as Open Workspace, and a race when toggling full screen during the join is fixed.
Fixes#678
Workspaces open several local project folders in one IDE session (File › New / Open / Manage Workspace…, or Attach when opening a project, which creates a workspace automatically for a plain project window). Member folders are the Project view roots and take part in indexing, Find in Files, Git, language servers, run configurations and builds; agent tasks choose which member they work in. Window › Merge All Project Windows groups project windows into one window with project tabs (switch, reorder, close, move to a new window), restored on reopen.
Closes#241Closes#198Closes#286
l0ng-ai