Traditional tab-based editor shell.
The default presentation shell: tab bar, file tree sidebar, split windows, modeline, picker, agent panel, and which-key popup. This is the UX that ships today.
Presentation fields live in MingaEditor.Shell.Traditional.State. The
Editor GenServer stores this as state.shell_state and dispatches
presentation events through the MingaEditor.Shell behaviour callbacks.
Migration status
Fields are being migrated from MingaEditor.State into
Shell.Traditional.State in batches. See BIG_REFACTOR_PLAN.md
Phase F for the full plan.
Batch 1 (current): nav_flash, hover_popup, dashboard, status_msg
Rendering architecture
Layout, chrome, and rendering are owned by modules under
Shell.Traditional.*: Layout, Chrome, and Renderer. These
currently delegate to Editor.* modules; the implementations will
move here as the shell independence refactor progresses.